draft-ietf-detnet-security-09.txt   draft-ietf-detnet-security-10.txt 
Internet Engineering Task Force T. Mizrahi Internet Engineering Task Force T. Mizrahi
Internet-Draft HUAWEI Internet-Draft HUAWEI
Intended status: Informational E. Grossman, Ed. Intended status: Informational E. Grossman, Ed.
Expires: September 19, 2020 DOLBY Expires: December 1, 2020 DOLBY
March 18, 2020 May 30, 2020
Deterministic Networking (DetNet) Security Considerations Deterministic Networking (DetNet) Security Considerations
draft-ietf-detnet-security-09 draft-ietf-detnet-security-10
Abstract Abstract
A DetNet (deterministic network) provides specific performance A DetNet (deterministic network) provides specific performance
guarantees to its data flows, such as extremely low data loss rates guarantees to its data flows, such as extremely low data loss rates
and bounded latency. As a result, securing a DetNet implies that in and bounded latency. As a result, securing a DetNet implies that in
addition to the best practice security measures taken for any addition to the best practice security measures taken for any
mission-critical network, additional security measures may be needed mission-critical network, additional security measures may be needed
whose purpose is exclusively to secure the intended operation of whose purpose is exclusively to secure the intended operation of
these novel service properties. This document addresses specifically these novel service properties.
those security considerations, with the assumption that the reader is
Designers of DetNet components (such as routers) that provide these
unique DetNet properties have the responsibility to uphold certain
security-related properties that can be assumed by DetNet system-
level designers. For example, the assumption that network traffic
associated with a given flow can never affect traffic associated with
a different flow is only true if the underlying components make it
so.
This document addresses DetNet-specific security considerations from
the perspective of both the DetNet component designer and the DetNet
system-level designer. It is assumed that both classes of reader are
already familiar with network security best practices for the data already familiar with network security best practices for the data
plane technologies underlying a given DetNet implementation. This plane technologies underlying a given DetNet implementation.
document defines a threat model and a taxonomy of relevant attacks, Component-level considerations include isolation of data flows from
including their potential impacts and mitigations. each other, ingress filtering, and detection and reporting of packet
arrival time violations. System-level considerations include a
threat model and a taxonomy of relevant attacks, including their
potential impacts and mitigations.
A given DetNet may require securing only certain aspects of DetNet A given DetNet may require securing only certain aspects of DetNet
performance, for example extremely low data loss rates but not performance, for example extremely low data loss rates but not
necessarily bounded latency. Therefore this document provides an necessarily bounded latency. Therefore this document provides an
association of threats against various use cases by industry, and association of threats against various use cases by industry, and
also against the individual service properties as defined in the also against the individual service properties as defined in the
DetNet Use Cases. DetNet Use Cases.
This document also addresses common DetNet security considerations This document also addresses common DetNet security considerations
related to the IP and MPLS data plane technologies (the first to be related to the IP and MPLS data plane technologies (the first to be
skipping to change at page 2, line 10 skipping to change at page 2, line 23
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This Internet-Draft will expire on September 19, 2020. This Internet-Draft will expire on December 1, 2020.
Copyright Notice Copyright Notice
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . 6 2. Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . 6
3. Security Threats . . . . . . . . . . . . . . . . . . . . . . 6 3. Security Considerations for DetNet Component Design . . . . . 7
3.1. Threat Model . . . . . . . . . . . . . . . . . . . . . . 6 3.1. Resource Allocation . . . . . . . . . . . . . . . . . . . 7
3.2. Threat Analysis . . . . . . . . . . . . . . . . . . . . . 7 3.2. Explicit Routes . . . . . . . . . . . . . . . . . . . . . 7
3.2.1. Delay . . . . . . . . . . . . . . . . . . . . . . . . 7 3.3. Redundant Path Support . . . . . . . . . . . . . . . . . 8
3.2.1.1. Delay Attack . . . . . . . . . . . . . . . . . . 7 3.4. Timing Violation Reporting . . . . . . . . . . . . . . . 9
3.2.2. DetNet Flow Modification or Spoofing . . . . . . . . 7 4. DetNet Security Considerations Compared With DiffServ
3.2.3. Resource Segmentation or Slicing . . . . . . . . . . 7 Security Considerations . . . . . . . . . . . . . . . . . . . 9
3.2.3.1. Inter-segment Attack . . . . . . . . . . . . . . 8 5. Security Threats . . . . . . . . . . . . . . . . . . . . . . 10
3.2.4. Packet Replication and Elimination . . . . . . . . . 8 5.1. Threat Model . . . . . . . . . . . . . . . . . . . . . . 10
3.2.4.1. Replication: Increased Attack Surface . . . . . . 8 5.2. Threat Analysis . . . . . . . . . . . . . . . . . . . . . 11
3.2.4.2. Replication-related Header Manipulation . . . . . 8 5.2.1. Delay . . . . . . . . . . . . . . . . . . . . . . . . 11
3.2.5. Path Choice . . . . . . . . . . . . . . . . . . . . . 9 5.2.1.1. Delay Attack . . . . . . . . . . . . . . . . . . 11
3.2.5.1. Path Manipulation . . . . . . . . . . . . . . . . 9 5.2.2. DetNet Flow Modification or Spoofing . . . . . . . . 11
3.2.5.2. Path Choice: Increased Attack Surface . . . . . . 9 5.2.3. Resource Segmentation or Slicing . . . . . . . . . . 11
3.2.6. Controller Plane . . . . . . . . . . . . . . . . . . 9 5.2.3.1. Inter-segment Attack . . . . . . . . . . . . . . 11
3.2.6.1. Control or Signaling Packet Modification . . . . 9 5.2.4. Packet Replication and Elimination . . . . . . . . . 12
3.2.6.2. Control or Signaling Packet Injection . . . . . . 9 5.2.4.1. Replication: Increased Attack Surface . . . . . . 12
3.2.7. Scheduling or Shaping . . . . . . . . . . . . . . . . 9 5.2.4.2. Replication-related Header Manipulation . . . . . 12
3.2.7.1. Reconnaissance . . . . . . . . . . . . . . . . . 9 5.2.5. Path Choice . . . . . . . . . . . . . . . . . . . . . 12
3.2.8. Time Synchronization Mechanisms . . . . . . . . . . . 9 5.2.5.1. Path Manipulation . . . . . . . . . . . . . . . . 12
3.3. Threat Summary . . . . . . . . . . . . . . . . . . . . . 10 5.2.5.2. Path Choice: Increased Attack Surface . . . . . . 13
4. Security Threat Impacts . . . . . . . . . . . . . . . . . . . 10 5.2.6. Controller Plane . . . . . . . . . . . . . . . . . . 13
4.1. Delay-Attacks . . . . . . . . . . . . . . . . . . . . . . 13 5.2.6.1. Control or Signaling Packet Modification . . . . 13
4.1.1. Data Plane Delay Attacks . . . . . . . . . . . . . . 13 5.2.6.2. Control or Signaling Packet Injection . . . . . . 13
4.1.2. Controller Plane Delay Attacks . . . . . . . . . . . 14 5.2.7. Scheduling or Shaping . . . . . . . . . . . . . . . . 13
4.2. Flow Modification and Spoofing . . . . . . . . . . . . . 14 5.2.7.1. Reconnaissance . . . . . . . . . . . . . . . . . 13
4.2.1. Flow Modification . . . . . . . . . . . . . . . . . . 14 5.2.8. Time Synchronization Mechanisms . . . . . . . . . . . 13
4.2.2. Spoofing . . . . . . . . . . . . . . . . . . . . . . 14 5.3. Threat Summary . . . . . . . . . . . . . . . . . . . . . 13
4.2.2.1. Dataplane Spoofing . . . . . . . . . . . . . . . 14 6. Security Threat Impacts . . . . . . . . . . . . . . . . . . . 14
4.2.2.2. Controller Plane Spoofing . . . . . . . . . . . . 15 6.1. Delay-Attacks . . . . . . . . . . . . . . . . . . . . . . 17
4.3. Segmentation attacks (injection) . . . . . . . . . . . . 15 6.1.1. Data Plane Delay Attacks . . . . . . . . . . . . . . 17
4.3.1. Data Plane Segmentation . . . . . . . . . . . . . . . 15 6.1.2. Controller Plane Delay Attacks . . . . . . . . . . . 18
4.3.2. Controller Plane Segmentation . . . . . . . . . . . . 15 6.2. Flow Modification and Spoofing . . . . . . . . . . . . . 18
4.4. Replication and Elimination . . . . . . . . . . . . . . . 16 6.2.1. Flow Modification . . . . . . . . . . . . . . . . . . 18
4.4.1. Increased Attack Surface . . . . . . . . . . . . . . 16 6.2.2. Spoofing . . . . . . . . . . . . . . . . . . . . . . 18
4.4.2. Header Manipulation at Elimination Routers . . . . . 16 6.2.2.1. Dataplane Spoofing . . . . . . . . . . . . . . . 18
4.5. Control or Signaling Packet Modification . . . . . . . . 16 6.2.2.2. Controller Plane Spoofing . . . . . . . . . . . . 19
4.6. Control or Signaling Packet Injection . . . . . . . . . . 16 6.3. Segmentation Attacks (injection) . . . . . . . . . . . . 19
4.7. Reconnaissance . . . . . . . . . . . . . . . . . . . . . 16 6.3.1. Data Plane Segmentation . . . . . . . . . . . . . . . 19
4.8. Attacks on Time Sync Mechanisms . . . . . . . . . . . . . 17 6.3.2. Controller Plane Segmentation . . . . . . . . . . . . 19
4.9. Attacks on Path Choice . . . . . . . . . . . . . . . . . 17 6.4. Replication and Elimination . . . . . . . . . . . . . . . 20
5. Security Threat Mitigation . . . . . . . . . . . . . . . . . 17 6.4.1. Increased Attack Surface . . . . . . . . . . . . . . 20
5.1. Path Redundancy . . . . . . . . . . . . . . . . . . . . . 17 6.4.2. Header Manipulation at Elimination Routers . . . . . 20
5.2. Integrity Protection . . . . . . . . . . . . . . . . . . 17 6.5. Control or Signaling Packet Modification . . . . . . . . 20
5.3. DetNet Node Authentication . . . . . . . . . . . . . . . 18 6.6. Control or Signaling Packet Injection . . . . . . . . . . 20
5.4. Dummy Traffic Insertion . . . . . . . . . . . . . . . . . 19 6.7. Reconnaissance . . . . . . . . . . . . . . . . . . . . . 20
5.5. Encryption . . . . . . . . . . . . . . . . . . . . . . . 19 6.8. Attacks on Time Sync Mechanisms . . . . . . . . . . . . . 21
5.5.1. Encryption Considerations for DetNet . . . . . . . . 19 6.9. Attacks on Path Choice . . . . . . . . . . . . . . . . . 21
5.6. Control and Signaling Message Protection . . . . . . . . 20 7. Security Threat Mitigation . . . . . . . . . . . . . . . . . 21
5.7. Dynamic Performance Analytics . . . . . . . . . . . . . . 21 7.1. Path Redundancy . . . . . . . . . . . . . . . . . . . . . 21
5.8. Mitigation Summary . . . . . . . . . . . . . . . . . . . 21 7.2. Integrity Protection . . . . . . . . . . . . . . . . . . 21
6. Association of Attacks to Use Cases . . . . . . . . . . . . . 23 7.3. DetNet Node Authentication . . . . . . . . . . . . . . . 22
6.1. Use Cases by Common Themes . . . . . . . . . . . . . . . 23 7.4. Dummy Traffic Insertion . . . . . . . . . . . . . . . . . 23
6.1.1. Sub-Network Layer . . . . . . . . . . . . . . . . . . 23 7.5. Encryption . . . . . . . . . . . . . . . . . . . . . . . 23
6.1.2. Central Administration . . . . . . . . . . . . . . . 24 7.5.1. Encryption Considerations for DetNet . . . . . . . . 23
6.1.3. Hot Swap . . . . . . . . . . . . . . . . . . . . . . 24 7.6. Control and Signaling Message Protection . . . . . . . . 24
6.1.4. Data Flow Information Models . . . . . . . . . . . . 25 7.7. Dynamic Performance Analytics . . . . . . . . . . . . . . 25
6.1.5. L2 and L3 Integration . . . . . . . . . . . . . . . . 25 7.8. Mitigation Summary . . . . . . . . . . . . . . . . . . . 25
6.1.6. End-to-End Delivery . . . . . . . . . . . . . . . . . 25 8. Association of Attacks to Use Cases . . . . . . . . . . . . . 27
6.1.7. Proprietary Deterministic Ethernet Networks . . . . . 26 8.1. Use Cases by Common Themes . . . . . . . . . . . . . . . 27
6.1.8. Replacement for Proprietary Fieldbuses . . . . . . . 26 8.1.1. Sub-Network Layer . . . . . . . . . . . . . . . . . . 27
6.1.9. Deterministic vs Best-Effort Traffic . . . . . . . . 26 8.1.2. Central Administration . . . . . . . . . . . . . . . 28
6.1.10. Deterministic Flows . . . . . . . . . . . . . . . . . 27 8.1.3. Hot Swap . . . . . . . . . . . . . . . . . . . . . . 28
6.1.11. Unused Reserved Bandwidth . . . . . . . . . . . . . . 27 8.1.4. Data Flow Information Models . . . . . . . . . . . . 29
6.1.12. Interoperability . . . . . . . . . . . . . . . . . . 27 8.1.5. L2 and L3 Integration . . . . . . . . . . . . . . . . 29
6.1.13. Cost Reductions . . . . . . . . . . . . . . . . . . . 28 8.1.6. End-to-End Delivery . . . . . . . . . . . . . . . . . 29
6.1.14. Insufficiently Secure Devices . . . . . . . . . . . . 28 8.1.7. Proprietary Deterministic Ethernet Networks . . . . . 30
6.1.15. DetNet Network Size . . . . . . . . . . . . . . . . . 28 8.1.8. Replacement for Proprietary Fieldbuses . . . . . . . 30
6.1.16. Multiple Hops . . . . . . . . . . . . . . . . . . . . 29 8.1.9. Deterministic vs Best-Effort Traffic . . . . . . . . 30
6.1.17. Level of Service . . . . . . . . . . . . . . . . . . 29 8.1.10. Deterministic Flows . . . . . . . . . . . . . . . . . 31
6.1.18. Bounded Latency . . . . . . . . . . . . . . . . . . . 29 8.1.11. Unused Reserved Bandwidth . . . . . . . . . . . . . . 31
6.1.19. Low Latency . . . . . . . . . . . . . . . . . . . . . 30 8.1.12. Interoperability . . . . . . . . . . . . . . . . . . 31
6.1.20. Bounded Jitter (Latency Variation) . . . . . . . . . 30 8.1.13. Cost Reductions . . . . . . . . . . . . . . . . . . . 32
6.1.21. Symmetrical Path Delays . . . . . . . . . . . . . . . 30 8.1.14. Insufficiently Secure Devices . . . . . . . . . . . . 32
6.1.22. Reliability and Availability . . . . . . . . . . . . 31 8.1.15. DetNet Network Size . . . . . . . . . . . . . . . . . 32
6.1.23. Redundant Paths . . . . . . . . . . . . . . . . . . . 31 8.1.16. Multiple Hops . . . . . . . . . . . . . . . . . . . . 33
6.1.24. Security Measures . . . . . . . . . . . . . . . . . . 31 8.1.17. Level of Service . . . . . . . . . . . . . . . . . . 33
6.2. Attack Types by Use Case Common Theme . . . . . . . . . . 31 8.1.18. Bounded Latency . . . . . . . . . . . . . . . . . . . 33
6.3. Security Considerations for OAM Traffic . . . . . . . . . 34 8.1.19. Low Latency . . . . . . . . . . . . . . . . . . . . . 34
7. DetNet Technology-Specific Threats . . . . . . . . . . . . . 34 8.1.20. Bounded Jitter (Latency Variation) . . . . . . . . . 34
7.1. IP . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 8.1.21. Symmetrical Path Delays . . . . . . . . . . . . . . . 34
7.2. MPLS . . . . . . . . . . . . . . . . . . . . . . . . . . 36 8.1.22. Reliability and Availability . . . . . . . . . . . . 34
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 37 8.1.23. Redundant Paths . . . . . . . . . . . . . . . . . . . 35
9. Security Considerations . . . . . . . . . . . . . . . . . . . 37 8.1.24. Security Measures . . . . . . . . . . . . . . . . . . 35
10. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 37 8.2. Attack Types by Use Case Common Theme . . . . . . . . . . 35
11. Informative References . . . . . . . . . . . . . . . . . . . 37 8.3. Security Considerations for OAM Traffic . . . . . . . . . 38
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 40 9. DetNet Technology-Specific Threats . . . . . . . . . . . . . 38
9.1. IP . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
9.2. MPLS . . . . . . . . . . . . . . . . . . . . . . . . . . 40
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 41
11. Security Considerations . . . . . . . . . . . . . . . . . . . 41
12. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 41
13. Informative References . . . . . . . . . . . . . . . . . . . 42
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 45
1. Introduction 1. Introduction
A deterministic network is one that can carry data flows for real- A deterministic network is one that can carry data flows for real-
time applications with extremely low data loss rates and bounded time applications with extremely low data loss rates and bounded
latency. Deterministic networks have been successfully deployed in latency. Deterministic networks have been successfully deployed in
real-time operational technology (OT) applications for some years. real-time operational technology (OT) applications for some years.
However, such networks are typically isolated from external access, However, such networks are typically isolated from external access,
and thus the security threat from external attackers is low. IETF and thus the security threat from external attackers is low. IETF
Deterministic Networking (DetNet) specifies a set of technologies Deterministic Networking (DetNet) specifies a set of technologies
that enable creation of deterministic networks on IP-based networks that enable creation of deterministic networks on IP-based networks
of potentially wide area (on the scale of a corporate network) of potentially wide area (on the scale of a corporate network)
potentially bringing the OT network into contact with Information potentially bringing the OT network into contact with Information
Technology (IT) traffic and security threats that lie outside of a Technology (IT) traffic and security threats that lie outside of a
tightly controlled and bounded area (such as the internals of an tightly controlled and bounded area (such as the internals of an
aircraft). These DetNet technologies have not previously been aircraft).
deployed together on a wide area IP-based network, and thus can
present security considerations that may be new to IP-based wide area These DetNet technologies have not previously been deployed together
network designers. This document, intended for use by DetNet network on a wide area IP-based network, and thus can present security
designers, provides insight into these security considerations. considerations that may be new to IP-based wide area network
designers; this document provides insight into such system-level
security considerations. In addition, designers of DetNet components
(such as routers) face new security-related challenges in providing
DetNet services, for example maintaining reliable isolation between
traffic flows in an environment where IT traffic co-mingles with
critical reserved-bandwidth OT traffic; this document also examines
security implications internal to DetNet components.
Security is of particularly high importance in DetNet networks Security is of particularly high importance in DetNet networks
because many of the use cases which are enabled by DetNet [RFC8578] because many of the use cases which are enabled by DetNet [RFC8578]
include control of physical devices (power grid components, include control of physical devices (power grid components,
industrial controls, building controls) which can have high industrial controls, building controls) which can have high
operational costs for failure, and present potentially attractive operational costs for failure, and present potentially attractive
targets for cyber-attackers. targets for cyber-attackers.
This situation is even more acute given that one of the goals of This situation is even more acute given that one of the goals of
DetNet is to provide a "converged network", i.e. one that includes DetNet is to provide a "converged network", i.e. one that includes
skipping to change at page 5, line 16 skipping to change at page 5, line 44
isolated from the IT network, for example [ARINC664P7]). Security isolated from the IT network, for example [ARINC664P7]). Security
considerations for OT networks are not a new area, and there are many considerations for OT networks are not a new area, and there are many
OT networks today that are connected to wide area networks or the OT networks today that are connected to wide area networks or the
Internet; this document focuses on the issues that are specific to Internet; this document focuses on the issues that are specific to
the DetNet technologies and use cases. the DetNet technologies and use cases.
Given the above considerations, securing a DetNet starts with a Given the above considerations, securing a DetNet starts with a
scrupulously well-designed and well-managed engineered network scrupulously well-designed and well-managed engineered network
following industry best practices for security at both the data plane following industry best practices for security at both the data plane
and controller plane; this is the assumed starting point for the and controller plane; this is the assumed starting point for the
considerations discussed herein. In this context we view the network considerations discussed herein. Such assumptions also depend on the
design and managment aspects of network security as being primarily network components themselves upholding the security-related
concerned with denial-of service prevention by ensuring that DetNet properties that are to be assumed by DetNet system-level designers;
traffic goes where it's supposed to and that an external attacker for example, the assumption that network traffic associated with a
can't inject traffic that disrupts the DetNet's delivery timing given flow can never affect traffic associated with a different flow
assurance. The time-specific aspects of DetNet security presented is only true if the underlying components make it so. Such
here take up where the design and management aspects leave off. properties, which may represent new challenges to component
designers, are also considered herein.
In this context we view the network design and management aspects of
network security as being primarily concerned with denial-of service
prevention by ensuring that DetNet traffic goes where it's supposed
to and that an external attacker can't inject traffic that disrupts
the DetNet's delivery timing assurance. The time-specific aspects of
DetNet security presented here take up where the design and
management aspects leave off.
The exact security requirements for any given DetNet network are The exact security requirements for any given DetNet network are
necessarily specific to the use cases handled by that network. Thus necessarily specific to the use cases handled by that network. Thus
the reader is assumed to be familiar with the specific security the reader is assumed to be familiar with the specific security
requirements of their use cases, for example those outlined in the requirements of their use cases, for example those outlined in the
DetNet Use Cases [RFC8578] and the Security Considerations sections DetNet Use Cases [RFC8578] and the Security Considerations sections
of the DetNet documents applicable to the network technologies in of the DetNet documents applicable to the network technologies in
use, for example [I-D.ietf-detnet-ip]). A general introduction to use, for example [I-D.ietf-detnet-ip]). A general introduction to
the DetNet architecture can be found in [RFC8655] and it is also the DetNet architecture can be found in [RFC8655] and it is also
recommended to be familiar with the Data Plane model recommended to be familiar with the Data Plane model
[I-D.ietf-detnet-data-plane-framework] and Flow Information Model [I-D.ietf-detnet-data-plane-framework] and Flow Information Model
[I-D.ietf-detnet-flow-information-model]. [I-D.ietf-detnet-flow-information-model].
The DetNet technologies include ways to: The DetNet technologies include ways to:
o Assign data plane resources for DetNet flows in some or all of the o Assign data plane resources for DetNet flows in some or all of the
intermediate nodes (routers) along the path of the flow intermediate nodes (routers) along the path of the flow
o Provide explicit routes for DetNet flows that do not rapidly o Provide explicit routes for DetNet flows that do not dynamically
change with the network topology change with the network topology in ways that affect the quality
of service received by the affected flow(s)
o Distribute data from DetNet flow packets over time and/or space to o Distribute data from DetNet flow packets over time and/or space to
ensure delivery of each packet's data' in spite of the loss of a ensure delivery of each packet's data' in spite of the loss of a
path path
This document includes sections on threat modeling and analysis, This document includes sections considering DetNet component design
threat impact and mitigation, and the association of attacks with use as well as system design. The latter include threat modeling and
cases based on the Use Case Common Themes section of the DetNet Use analysis, threat impact and mitigation, and the association of
Cases. attacks with use cases (based on the Use Case Common Themes section
of the DetNet Use Cases).
The structure of the threat model and threat analysis sections were
originally derived from [RFC7384], which also considers time-related
security considerations in IP networks.
2. Abbreviations 2. Abbreviations
IT Information technology (the application of computers to IT Information technology (the application of computers to
store, study, retrieve, transmit, and manipulate data or information, store, study, retrieve, transmit, and manipulate data or information,
often in the context of a business or other enterprise - Wikipedia). often in the context of a business or other enterprise - Wikipedia).
OT Operational Technology (the hardware and software OT Operational Technology (the hardware and software
dedicated to detecting or causing changes in physical processes dedicated to detecting or causing changes in physical processes
through direct monitoring and/or control of physical devices such as through direct monitoring and/or control of physical devices such as
valves, pumps, etc. - Wikipedia) valves, pumps, etc. - Wikipedia)
MITM Man in the Middle MITM Man in the Middle
3. Security Threats 3. Security Considerations for DetNet Component Design
As noted above, DetNet provides resource allocation, explicit routes
and redundant path support. Each of these have associated security
implications, which are discussed in this section, in the context of
component design. Detection, reporting and appropriate action in the
case of packet arrival time violations are also discussed.
3.1. Resource Allocation
A DetNet system security designer relies on the premise that any
resources allocated to a resource-reserved (OT-type) flow are
inviolable, in other words there is no physical possibility within a
DetNet component that resources allocated to a given flow can be
compromised by any type of traffic in the network; this includes both
malicious traffic as well as inadvertent traffic such as might be
produced by a malfunctioning component, for example one made by a
different manufacturer. From a security standpoint, this is a
critical assumption, for example when designing against DOS attacks.
It is the responsibility of the component designer to ensure that
this condition is met; this implies protection against excess traffic
from adjacent flows, and against compromises to the resource
allocation/deallocation process.
3.2. Explicit Routes
The DetNet-specific purpose for constraining the network's ability to
re-route OT traffic is to maintain the specified service parameters
(such as upper and lower latency boundaries) for a given flow. For
example if the network were to re-route a flow (or some part of a
flow) based exclusively on statistical path usage metrics, or due to
malicious activity, it is possible that the new path would have a
latency that is outside the required latency bounds which were
designed into the original TE-designed path, thereby violating the
quality of service for the affected flow (or part of that flow).
(However, is acceptable for the network to re-route OT traffic in
such a way as to maintain the specified latency bounds (and any other
specified service properties) for any reason, for example in response
to a runtime component or path failure). From a security standpoint,
the system designer relies on the premise that the packets will be
delivered with the specified latency boundaries; thus any component
that is involved in controlling or implementing any change of the
initially TE-configured flow routes needs to prevent malicious or
accidental re-routing of OT flows that might adversely affect
delivering the traffic within the specified service parameters.
3.3. Redundant Path Support
The DetNet provision for redundant paths (PREOF) (as defined in the
DetNet Architecture [RFC8655]) provides the foundation for high
reliablity of a DetNet, by virtually eliminating packet loss (i.e. to
a degree which is implementation-dependent) through hitless redundant
packet delivery. (Note that PREOF is not defined for a DetNet IP
data plane).
It is the responsibility of the system designer to determine the
level of reliability required by their use case, and to specify
redundant paths sufficient to provide the desired level of
reliability (in as much as that reliability can be provided through
the use of redundant paths). It is the responsibility of the
component designer to ensure that the relevant PREOF operations are
executed reliably and securely. (However, note that not all PREOF
operations are necessarily implemented in every network; for example
a packet re-ordering function may not be necessary if the packets are
either not required to be in order, or if the ordering is performed
in some other part of the network.)
As noted in Section 7.2, Packet Sequence Number Integrity
Considerations, there is a trust relationship between the pair of
devices that replicate and remove packets, so it is the
responsibility of the system designer to define these relationships
with the appropriate security considerations, and the components must
each uphold the security rights implied by these relationships.
Ideally a redundant path could be specified from end to end of the
flow's path, however given that this is not always possible (as
described in [RFC8655]) the system designer will need to consider the
resulting end-to-end reliability and security resulting from any
given arrangment of network segments along the path, each of which
provides its individual PREOF implementation and thus its individual
level of reliabiilty and security.
At the data plane the implementation of PREOF depends on the correct
assignment and interpretation of packet sequence numbers, as well as
the actions taken based on them, such as elimination. Thus the
integrity of these values must be maintained by the component as they
are assigned by the DetNet data plane's Service sub-layer, and
transported by the Forwarding sub-layer.
3.4. Timing Violation Reporting
Another fundamental assumption of a secure DetNet is that in any case
in which an incoming packet arrives outside of its prescribed time
window or exceeding the reserved flow bandwidth, something can be
done about it. That means that the component's data plane must be
able to detect such cases, then at least alert the control plane,
and/or drop the packet, and/or shut down the link if violations
persist. Logging of such issues may not be adequate, since a delay
in response to the situation could result in material damage, for
example to mechanical devices controlled by the network.
4. DetNet Security Considerations Compared With DiffServ Security
Considerations
DetNet is designed to be compatible with DiffServ [RFC2474] as
applied to IT traffic in the DetNet. DetNet also incorporates the
use of the 6-bit value of the DSCP field of the TOS field of the IP
header for flow identification for OT traffic, however the DetNet
interpretation of the DSCP value for OT traffic is not equivalent to
the PHB selection behavior as defined by DiffServ.
Thus security consideration for DetNet have some aspects in common
with DiffServ, in fact overlapping 100% with respect to IP IT
traffic. Security considerations for these aspects are part of the
existing literature on IP network security, specifically the Security
sections of [RFC2474] and [RFC2475]. However DetNet also introduce
timing and other considerations which are not present in DiffServ, so
the DiffServ security considerations are necessary but not sufficient
for DetNet.
In the case of DetNet OT traffic, the DSCP value, although
interpreted differently than in DiffServ, does contribute to
determination of the service provided to the packet. Thus in DetNet
there are similar consequences to DiffServ for lack of detection of,
or incorrect handling of, packets with mismarked DSCP values, and
thus many of the points made in the DiffServ draft Security
discussions are also relevant to DetNet OT traffic, though perhaps in
modified form. For example, in DetNet the effect of an undetected or
incorrectly handled maliciously mismarked DSCP field in an OT packet
is not identical to affecting that packet's PHB, since DetNet does
not use the PHB concept for OT traffic, but nonetheless the service
provided to the packet could be affected, so mitigation measures
analogous to those prescribed by DiffServ would be appropriate for
DetNet. For example, mismarked DSCP values should not cause failure
of network nodes, and any internal link that cannot be adequately
secured against modification of DSCP values should be treated as a
boundary link (and hence any arriving traffic on that link is treated
as if it were entering the domain at an ingress node). The remarks
in [RFC2474] regarding IPsec and Tunnelling Interactions are also
relevant (though this is not to say that other sections are less
relevant).
5. Security Threats
This section presents a threat model, and analyzes the possible This section presents a threat model, and analyzes the possible
threats in a DetNet-enabled network. The threats considered in this threats in a DetNet-enabled network. The threats considered in this
section are independent of any specific technologies used to section are independent of any specific technologies used to
implement the DetNet; Section 7) considers attacks that are implement the DetNet; Section 9) considers attacks that are
associated with the DetNet technologies encompassed by associated with the DetNet technologies encompassed by
[I-D.ietf-detnet-data-plane-framework]. [I-D.ietf-detnet-data-plane-framework].
We distinguish controller plane threats from data plane threats. The We distinguish controller plane threats from data plane threats. The
attack surface may be the same, but the types of attacks as well as attack surface may be the same, but the types of attacks as well as
the motivation behind them, are different. For example, a delay the motivation behind them, are different. For example, a delay
attack is more relevant to data plane than to controller plane. attack is more relevant to data plane than to controller plane.
There is also a difference in terms of security solutions: the way There is also a difference in terms of security solutions: the way
you secure the data plane is often different than the way you secure you secure the data plane is often different than the way you secure
the controller plane. the controller plane.
3.1. Threat Model 5.1. Threat Model
The threat model used in this memo is based on the threat model of The threat model used in this memo is based on the threat model of
Section 3.1 of [RFC7384]. This model classifies attackers based on Section 3.1 of [RFC7384]. This model classifies attackers based on
two criteria: two criteria:
o Internal vs. external: internal attackers either have access to a o Internal vs. external: internal attackers either have access to a
trusted segment of the network or possess the encryption or trusted segment of the network or possess the encryption or
authentication keys. External attackers, on the other hand, do authentication keys. External attackers, on the other hand, do
not have the keys and have access only to the encrypted or not have the keys and have access only to the encrypted or
authenticated traffic. authenticated traffic.
o Man in the Middle (MITM) vs. packet injector: MITM attackers are o Man in the Middle (MITM) vs. packet injector: MITM attackers are
located in a position that allows interception and modification of located in a position that allows interception and modification of
in-flight protocol packets, whereas a traffic injector can only in-flight protocol packets, whereas a traffic injector can only
attack by generating protocol packets. attack by generating protocol packets.
Care has also been taken to adhere to Section 5 of [RFC3552], both Care has also been taken to adhere to Section 5 of [RFC3552], both
with respect to which attacks are considered out-of-scope for this with respect to which attacks are considered out-of-scope for this
document, but also which are considered to be the most common threats document, but also which are considered to be the most common threats
(explored further in Section 3.2. Most of the direct threats to (explored further in Section 5.2 (Threat Analysis). Most of the
DetNet are active attacks, but it is highly suggested that DetNet direct threats to DetNet are active attacks, but it is highly
application developers take appropriate measures to protect the suggested that DetNet application developers take appropriate
content of the DetNet flows from passive attacks. measures to protect the content of the DetNet flows from passive
attacks.
DetNet-Service, one of the service scenarios described in DetNet-Service, one of the service scenarios described in
[I-D.varga-detnet-service-model], is the case where a service [I-D.varga-detnet-service-model], is the case where a service
connects DetNet networking islands, i.e. two or more otherwise connects DetNet networking islands, i.e. two or more otherwise
independent DetNet network domains are connected via a link that is independent DetNet network domains are connected via a link that is
not intrinsically part of either network. This implies that there not intrinsically part of either network. This implies that there
could be DetNet traffic flowing over a non-DetNet link, which may could be DetNet traffic flowing over a non-DetNet link, which may
provide an attacker with an advantageous opportunity to tamper with provide an attacker with an advantageous opportunity to tamper with
DetNet traffic. The security properties of non-DetNet links are DetNet traffic. The security properties of non-DetNet links are
outside of the scope of DetNet Security, but it should be noted that outside of the scope of DetNet Security, but it should be noted that
use of non-DetNet services to interconnect DetNet networks merits use of non-DetNet services to interconnect DetNet networks merits
security analysis to ensure the integrity of the DetNet networks security analysis to ensure the integrity of the DetNet networks
involved. involved.
3.2. Threat Analysis 5.2. Threat Analysis
3.2.1. Delay 5.2.1. Delay
3.2.1.1. Delay Attack 5.2.1.1. Delay Attack
An attacker can maliciously delay DetNet data flow traffic. By An attacker can maliciously delay DetNet data flow traffic. By
delaying the traffic, the attacker can compromise the service of delaying the traffic, the attacker can compromise the service of
applications that are sensitive to high delays or to high delay applications that are sensitive to high delays or to high delay
variation. The delay may be constant or modulated. variation. The delay may be constant or modulated.
3.2.2. DetNet Flow Modification or Spoofing 5.2.2. DetNet Flow Modification or Spoofing
An attacker can modify some header fields of en route packets in a An attacker can modify some header fields of en route packets in a
way that causes the DetNet flow identification mechanisms to way that causes the DetNet flow identification mechanisms to
misclassify the flow. Alternatively, the attacker can inject traffic misclassify the flow. Alternatively, the attacker can inject traffic
that is tailored to appear as if it belongs to a legitimate DetNet that is tailored to appear as if it belongs to a legitimate DetNet
flow. The potential consequence is that the DetNet flow resource flow. The potential consequence is that the DetNet flow resource
allocation cannot guarantee the performance that is expected when the allocation cannot guarantee the performance that is expected when the
flow identification works correctly. flow identification works correctly.
3.2.3. Resource Segmentation or Slicing 5.2.3. Resource Segmentation or Slicing
3.2.3.1. Inter-segment Attack
5.2.3.1. Inter-segment Attack
An attacker can inject traffic that will consume network resources An attacker can inject traffic that will consume network resources
such that it affects DetNet flows. This can be performed using non- such that it affects DetNet flows. This can be performed using non-
DetNet traffic that indirectly affects DetNet traffic (hardware DetNet traffic that indirectly affects DetNet traffic (hardware
resource exhaustion), or by using DetNet traffic from one DetNet flow resource exhaustion), or by using DetNet traffic from one DetNet flow
that directly affects traffic from different DetNet flows. that directly affects traffic from different DetNet flows.
3.2.4. Packet Replication and Elimination 5.2.4. Packet Replication and Elimination
3.2.4.1. Replication: Increased Attack Surface 5.2.4.1. Replication: Increased Attack Surface
Redundancy is intended to increase the robustness and survivability Redundancy is intended to increase the robustness and survivability
of DetNet flows, and replication over multiple paths can potentially of DetNet flows, and replication over multiple paths can potentially
mitigate an attack that is limited to a single path. However, the mitigate an attack that is limited to a single path. However, the
fact that packets are replicated over multiple paths increases the fact that packets are replicated over multiple paths increases the
attack surface of the network, i.e., there are more points in the attack surface of the network, i.e., there are more points in the
network that may be subject to attacks. network that may be subject to attacks.
3.2.4.2. Replication-related Header Manipulation 5.2.4.2. Replication-related Header Manipulation
An attacker can manipulate the replication-related header fields An attacker can manipulate the replication-related header fields
(R-TAG). This capability opens the door for various types of (R-TAG). This capability opens the door for various types of
attacks. For example: attacks. For example:
o Forward both replicas - malicious change of a packet SN (Sequence o Forward both replicas - malicious change of a packet SN (Sequence
Number) can cause both replicas of the packet to be forwarded. Number) can cause both replicas of the packet to be forwarded.
Note that this attack has a similar outcome to a replay attack. Note that this attack has a similar outcome to a replay attack.
o Eliminate both replicas - SN manipulation can be used to cause o Eliminate both replicas - SN manipulation can be used to cause
skipping to change at page 9, line 5 skipping to change at page 12, line 45
every SN value S with a higher value S+C, where C is a constant every SN value S with a higher value S+C, where C is a constant
integer. Thus, the attacker creates a false illusion that the integer. Thus, the attacker creates a false illusion that the
attacked path has the lowest delay, causing all packets from other attacked path has the lowest delay, causing all packets from other
paths to be eliminated in favor of the attacked path. Once the paths to be eliminated in favor of the attacked path. Once the
flow from the compromised path is favored by the elminating flow from the compromised path is favored by the elminating
bridge, the flow is hijacked by the attacker. It is now posible bridge, the flow is hijacked by the attacker. It is now posible
to either replace en route packets with malicious packets, or to either replace en route packets with malicious packets, or
simply injecting errors, causing the packets to be dropped at simply injecting errors, causing the packets to be dropped at
their destination. their destination.
3.2.5. Path Choice 5.2.5. Path Choice
3.2.5.1. Path Manipulation 5.2.5.1. Path Manipulation
An attacker can maliciously change, add, or remove a path, thereby An attacker can maliciously change, add, or remove a path, thereby
affecting the corresponding DetNet flows that use the path. affecting the corresponding DetNet flows that use the path.
3.2.5.2. Path Choice: Increased Attack Surface 5.2.5.2. Path Choice: Increased Attack Surface
One of the possible consequences of a path manipulation attack is an One of the possible consequences of a path manipulation attack is an
increased attack surface. Thus, when the attack described in the increased attack surface. Thus, when the attack described in the
previous subsection is implemented, it may increase the potential of previous subsection is implemented, it may increase the potential of
other attacks to be performed. other attacks to be performed.
3.2.6. Controller Plane 5.2.6. Controller Plane
3.2.6.1. Control or Signaling Packet Modification 5.2.6.1. Control or Signaling Packet Modification
An attacker can maliciously modify en route control packets in order An attacker can maliciously modify en route control packets in order
to disrupt or manipulate the DetNet path/resource allocation. to disrupt or manipulate the DetNet path/resource allocation.
3.2.6.2. Control or Signaling Packet Injection 5.2.6.2. Control or Signaling Packet Injection
An attacker can maliciously inject control packets in order to An attacker can maliciously inject control packets in order to
disrupt or manipulate the DetNet path/resource allocation. disrupt or manipulate the DetNet path/resource allocation.
3.2.7. Scheduling or Shaping 5.2.7. Scheduling or Shaping
3.2.7.1. Reconnaissance 5.2.7.1. Reconnaissance
A passive eavesdropper can identify DetNet flows and then gather A passive eavesdropper can identify DetNet flows and then gather
information about en route DetNet flows, e.g., the number of DetNet information about en route DetNet flows, e.g., the number of DetNet
flows, their bandwidths, their schedules, or other temporal flows, their bandwidths, their schedules, or other temporal
properties. The gathered information can later be used to invoke properties. The gathered information can later be used to invoke
other attacks on some or all of the flows. other attacks on some or all of the flows.
Note that in some cases DetNet flows may be identified based on an Note that in some cases DetNet flows may be identified based on an
explicit DetNet header, but in some cases the flow identification may explicit DetNet header, but in some cases the flow identification may
be based on fields from the L3/L4 headers. If L3/L4 headers are be based on fields from the L3/L4 headers. If L3/L4 headers are
involved, for purposes of this document we assume they are encrypted involved, for purposes of this document we assume they are encrypted
and/or integrity-protected from external attackers. and/or integrity-protected from external attackers.
3.2.8. Time Synchronization Mechanisms 5.2.8. Time Synchronization Mechanisms
An attacker can use any of the attacks described in [RFC7384] to An attacker can use any of the attacks described in [RFC7384] to
attack the synchronization protocol, thus affecting the DetNet attack the synchronization protocol, thus affecting the DetNet
service. service.
3.3. Threat Summary 5.3. Threat Summary
A summary of the attacks that were discussed in this section is A summary of the attacks that were discussed in this section is
presented in Figure 1. For each attack, the table specifies the type presented in Figure 1. For each attack, the table specifies the type
of attackers that may invoke the attack. In the context of this of attackers that may invoke the attack. In the context of this
summary, the distinction between internal and external attacks is summary, the distinction between internal and external attacks is
under the assumption that a corresponding security mechanism is being under the assumption that a corresponding security mechanism is being
used, and that the corresponding network equipment takes part in this used, and that the corresponding network equipment takes part in this
mechanism. mechanism.
+-----------------------------------------+----+----+----+----+ +-----------------------------------------+----+----+----+----+
skipping to change at page 10, line 46 skipping to change at page 14, line 38
+-----------------------------------------+----+----+----+----+ +-----------------------------------------+----+----+----+----+
|Control or Signaling Packet Injection | | + | | | |Control or Signaling Packet Injection | | + | | |
+-----------------------------------------+----+----+----+----+ +-----------------------------------------+----+----+----+----+
|Reconnaissance | + | | + | | |Reconnaissance | + | | + | |
+-----------------------------------------+----+----+----+----+ +-----------------------------------------+----+----+----+----+
|Attacks on Time Sync Mechanisms | + | + | + | + | |Attacks on Time Sync Mechanisms | + | + | + | + |
+-----------------------------------------+----+----+----+----+ +-----------------------------------------+----+----+----+----+
Figure 1: Threat Analysis Summary Figure 1: Threat Analysis Summary
4. Security Threat Impacts 6. Security Threat Impacts
This section describes and rates the impact of the attacks described This section describes and rates the impact of the attacks described
in Section 3. In this section, the impacts as described assume that in Section 5, Security Threats. In this section, the impacts as
the associated mitigation is not present or has failed. Mitigations described assume that the associated mitigation is not present or has
are discussed in Section 5. failed. Mitigations are discussed in Section 7, Security Threat
Mitigation.
In computer security, the impact (or consequence) of an incident can In computer security, the impact (or consequence) of an incident can
be measured in loss of confidentiality, integrity or availability of be measured in loss of confidentiality, integrity or availability of
information. In the case of time sensitive networks, the impact of a information. In the case of time sensitive networks, the impact of a
network exploit can also include failure or malfunction of mechanical network exploit can also include failure or malfunction of mechanical
and/or other OT systems. and/or other OT systems.
DetNet raises these stakes significantly for OT applications, DetNet raises these stakes significantly for OT applications,
particularly those which may have been designed to run in an OT-only particularly those which may have been designed to run in an OT-only
environment and thus may not have been designed for security in an IT environment and thus may not have been designed for security in an IT
skipping to change at page 13, line 34 skipping to change at page 17, line 28
| Src Node Integ | Hi | Hi | Hi | | Src Node Integ | Hi | Hi | Hi |
+------------------+--------------------------+ +------------------+--------------------------+
| Availability | Hi | Hi | Hi | | Availability | Hi | Hi | Hi |
+------------------+--------------------------+ +------------------+--------------------------+
Figure 2: Impact of Attacks by Use Case Industry Figure 2: Impact of Attacks by Use Case Industry
The rest of this section will cover impact of the different groups in The rest of this section will cover impact of the different groups in
more detail. more detail.
4.1. Delay-Attacks 6.1. Delay-Attacks
4.1.1. Data Plane Delay Attacks 6.1.1. Data Plane Delay Attacks
Note that 'delay attack' also includes the possibility of a 'negative Note that 'delay attack' also includes the possibility of a 'negative
delay' or early arrival of a packet, or possibly adversely changing delay' or early arrival of a packet, or possibly adversely changing
the timestamp value. the timestamp value.
Delayed messages in a DetNet link can result in the same behavior as Delayed messages in a DetNet link can result in the same behavior as
dropped messages in ordinary networks as the services attached to the dropped messages in ordinary networks as the services attached to the
DetNet flow have strict deterministic requirements. DetNet flow have strict deterministic requirements.
For a single path scenario, disruption is a real possibility, whereas For a single path scenario, disruption is a real possibility, whereas
in a multipath scenario, large delays or instabilities in one DetNet in a multipath scenario, large delays or instabilities in one DetNet
flow can lead to increased buffer and processor resources at the flow can lead to increased buffer and processor resources at the
eliminating router. eliminating router.
A data-plane delay attack on a system controlling substantial moving A data-plane delay attack on a system controlling substantial moving
devices, for example in industrial automation, can cause physical devices, for example in industrial automation, can cause physical
damage. For example, if the network promises a bounded latency of damage. For example, if the network promises a bounded latency of
2ms for a flow, yet the machine receives it with 5ms latency, the 2ms for a flow, yet the machine receives it with 5ms latency, the
machine's control loop can become unstable. machine's control loop can become unstable.
4.1.2. Controller Plane Delay Attacks 6.1.2. Controller Plane Delay Attacks
In and of itself, this is not directly a threat to the DetNet In and of itself, this is not directly a threat to the DetNet
service, but the effects of delaying control messages can have quite service, but the effects of delaying control messages can have quite
adverse effects later. adverse effects later.
o Delayed tear-down can lead to resource leakage, which in turn can o Delayed tear-down can lead to resource leakage, which in turn can
result in failure to allocate new DetNet flows, finally giving result in failure to allocate new DetNet flows, finally giving
rise to a denial of service attack. rise to a denial of service attack.
o Failure to deliver, or severely delaying, controller plane o Failure to deliver, or severely delaying, controller plane
messages adding an endpoint to a multicast-group will prevent the messages adding an endpoint to a multicast-group will prevent the
new endpoint from receiving expected frames thus disrupting new endpoint from receiving expected frames thus disrupting
expected behavior. expected behavior.
o Delaying messages removing an endpoint from a group can lead to o Delaying messages removing an endpoint from a group can lead to
loss of privacy as the endpoint will continue to receive messages loss of privacy as the endpoint will continue to receive messages
even after it is supposedly removed. even after it is supposedly removed.
4.2. Flow Modification and Spoofing 6.2. Flow Modification and Spoofing
4.2.1. Flow Modification 6.2.1. Flow Modification
If the contents of a packet header or body can be modified by the If the contents of a packet header or body can be modified by the
attacker, this can cause the packet to be routed incorrectly or attacker, this can cause the packet to be routed incorrectly or
dropped, or the payload to be corrupted or subtly modified. dropped, or the payload to be corrupted or subtly modified.
4.2.2. Spoofing 6.2.2. Spoofing
4.2.2.1. Dataplane Spoofing 6.2.2.1. Dataplane Spoofing
Spoofing dataplane messages can result in increased resource Spoofing dataplane messages can result in increased resource
consumptions on the routers throughout the network as it will consumptions on the routers throughout the network as it will
increase buffer usage and processor utilization. This can lead to increase buffer usage and processor utilization. This can lead to
resource exhaustion and/or increased delay. resource exhaustion and/or increased delay.
If the attacker manages to create valid headers, the false messages If the attacker manages to create valid headers, the false messages
can be forwarded through the network, using part of the allocated can be forwarded through the network, using part of the allocated
bandwidth. This in turn can cause legitimate messages to be dropped bandwidth. This in turn can cause legitimate messages to be dropped
when the resource budget has been exhausted. when the resource budget has been exhausted.
Finally, the endpoint will have to deal with invalid messages being Finally, the endpoint will have to deal with invalid messages being
delivered to the endpoint instead of (or in addition to) a valid delivered to the endpoint instead of (or in addition to) a valid
message. message.
4.2.2.2. Controller Plane Spoofing 6.2.2.2. Controller Plane Spoofing
A successful controller plane spoofing-attack will potentionally have A successful controller plane spoofing-attack will potentionally have
adverse effects. It can do virtually anything from: adverse effects. It can do virtually anything from:
o modifying existing DetNet flows by changing the available o modifying existing DetNet flows by changing the available
bandwidth bandwidth
o add or remove endpoints from a DetNet flow o add or remove endpoints from a DetNet flow
o drop DetNet flows completely o drop DetNet flows completely
o falsely create new DetNet flows (exhaust the systems resources, or o falsely create new DetNet flows (exhaust the systems resources, or
to enable DetNet flows that are outside the Network Engineer's to enable DetNet flows that are outside the Network Engineer's
control) control)
4.3. Segmentation attacks (injection) 6.3. Segmentation Attacks (injection)
4.3.1. Data Plane Segmentation 6.3.1. Data Plane Segmentation
Injection of false messages in a DetNet flow could lead to exhaustion Injection of false messages in a DetNet flow could lead to exhaustion
of the available bandwidth for that flow if the routers attribute of the available bandwidth for that flow if the routers attribute
these false messages to that flow's budget. these false messages to that flow's budget.
In a multipath scenario, injected messages will cause increased In a multipath scenario, injected messages will cause increased
processor utilization in elimination routers. If enough paths are processor utilization in elimination routers. If enough paths are
subject to malicious injection, the legitimate messages can be subject to malicious injection, the legitimate messages can be
dropped. Likewise it can cause an increase in buffer usage. In dropped. Likewise it can cause an increase in buffer usage. In
total, it will consume more resources in the routers than normal, total, it will consume more resources in the routers than normal,
giving rise to a resource exhaustion attack on the routers. giving rise to a resource exhaustion attack on the routers.
If a DetNet flow is interrupted, the end application will be affected If a DetNet flow is interrupted, the end application will be affected
by what is now a non-deterministic flow. by what is now a non-deterministic flow.
4.3.2. Controller Plane Segmentation 6.3.2. Controller Plane Segmentation
In a successful controller plane segmentation attack, control In a successful controller plane segmentation attack, control
messages are acted on by nodes in the network, unbeknownst to the messages are acted on by nodes in the network, unbeknownst to the
central controller or the network engineer. This has the potential central controller or the network engineer. This has the potential
to: to:
o create new DetNet flows (exhausting resources) o create new DetNet flows (exhausting resources)
o drop existing DetNet flows (denial of service) o drop existing DetNet flows (denial of service)
o add/remove end-stations to a multicast group (loss of privacy) o add/remove end-stations to a multicast group (loss of privacy)
o modify the DetNet flow attributes (affecting available bandwidth o modify the DetNet flow attributes (affecting available bandwidth
4.4. Replication and Elimination 6.4. Replication and Elimination
The Replication and Elimination is relevant only to Data Plane The Replication and Elimination is relevant only to Data Plane
messages as controller plane messages are not subject to multipath messages as controller plane messages are not subject to multipath
routing. routing.
4.4.1. Increased Attack Surface 6.4.1. Increased Attack Surface
Covered briefly in Section 4.3 Covered briefly in Section 6.3, Segmentation Attacks.
4.4.2. Header Manipulation at Elimination Routers 6.4.2. Header Manipulation at Elimination Routers
Covered briefly in Section 4.3 Covered briefly in Section 6.3, Segmentation Attacks.
4.5. Control or Signaling Packet Modification 6.5. Control or Signaling Packet Modification
If control packets are subject to manipulation undetected, the If control packets are subject to manipulation undetected, the
network can be severely compromised. network can be severely compromised.
4.6. Control or Signaling Packet Injection 6.6. Control or Signaling Packet Injection
If an attacker can inject control packets undetected, the network can If an attacker can inject control packets undetected, the network can
be severely compromised. be severely compromised.
4.7. Reconnaissance 6.7. Reconnaissance
Of all the attacks, this is one of the most difficult to detect and Of all the attacks, this is one of the most difficult to detect and
counter. Often, an attacker will start out by observing the traffic counter. Often, an attacker will start out by observing the traffic
going through the network and use the knowledge gathered in this going through the network and use the knowledge gathered in this
phase to mount future attacks. phase to mount future attacks.
The attacker can, at their leisure, observe over time all aspects of The attacker can, at their leisure, observe over time all aspects of
the messaging and signalling, learning the intent and purpose of all the messaging and signalling, learning the intent and purpose of all
traffic flows. At some later date, possibly at an important time in traffic flows. At some later date, possibly at an important time in
an operational context, the attacker can launch a multi-faceted an operational context, the attacker can launch a multi-faceted
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The flow-id in the header of the data plane-messages gives an The flow-id in the header of the data plane-messages gives an
attacker a very reliable identifier for DetNet traffic, and this attacker a very reliable identifier for DetNet traffic, and this
traffic has a high probability of going to lucrative targets. traffic has a high probability of going to lucrative targets.
Applications which are ported from a private OT network to the higher Applications which are ported from a private OT network to the higher
visibility DetNet environment may need to be adapted to limit visibility DetNet environment may need to be adapted to limit
distinctive flow properties that could make them susceptible to distinctive flow properties that could make them susceptible to
reconnaissance. reconnaissance.
4.8. Attacks on Time Sync Mechanisms 6.8. Attacks on Time Sync Mechanisms
Attacks on time sync mechanisms are addressed in [RFC7384]. Attacks on time sync mechanisms are addressed in [RFC7384].
4.9. Attacks on Path Choice 6.9. Attacks on Path Choice
This is covered in part in Section 4.3, and as with Replication and This is covered in part in Section 6.3, Segmentation Attacks, and as
Elimination (Section 4.4), this is relevant for DataPlane messages. with Replication and Elimination (Section 6.4), this is relevant for
DataPlane messages.
5. Security Threat Mitigation 7. Security Threat Mitigation
This section describes a set of measures that can be taken to This section describes a set of measures that can be taken to
mitigate the attacks described in Section 3. These mitigations mitigate the attacks described in Section 5, Security Threats. These
should be viewed as a toolset that includes several different and mitigations should be viewed as a toolset that includes several
diverse tools. Each application or system will typically use a different and diverse tools. Each application or system will
subset of these tools, based on a system-specific threat analysis. typically use a subset of these tools, based on a system-specific
threat analysis.
5.1. Path Redundancy 7.1. Path Redundancy
Description Description
A DetNet flow that can be forwarded simultaneously over multiple A DetNet flow that can be forwarded simultaneously over multiple
paths. Path replication and elimination [RFC8655] provides paths. Path replication and elimination [RFC8655] provides
resiliency to dropped or delayed packets. This redundancy resiliency to dropped or delayed packets. This redundancy
improves the robustness to failures and to man-in-the-middle improves the robustness to failures and to man-in-the-middle
attacks. attacks. Note: At the time of this writing, PREOF is not defined
for the IP data plane.
Related attacks Related attacks
Path redundancy can be used to mitigate various man-in-the-middle Path redundancy can be used to mitigate various man-in-the-middle
attacks, including attacks described in Section 3.2.1, attacks, including attacks described in Section 5.2.1,
Section 3.2.2, Section 3.2.3, and Section 3.2.8. However it is Section 5.2.2, Section 5.2.3, and Section 5.2.8. However it is
also possible that multiple paths may make it more difficult to also possible that multiple paths may make it more difficult to
locate the source of a MITM attacker. locate the source of a MITM attacker.
A delay modulation attack could result in extensively exercising A delay modulation attack could result in extensively exercising
parts of the code that wouldn't normally be extensively exercised parts of the code that wouldn't normally be extensively exercised
and thus might expose flaws in the system that might otherwise not and thus might expose flaws in the system that might otherwise not
be exposed. be exposed.
5.2. Integrity Protection 7.2. Integrity Protection
Description Description
An integrity protection mechanism, such as a Hash-based Message An integrity protection mechanism, such as a Hash-based Message
Authentication Code (HMAC) can be used to mitigate modification Authentication Code (HMAC) can be used to mitigate modification
attacks on IP packets. Integrity protection in the controller attacks on IP packets. Integrity protection in the controller
plane is discussed in Section 5.6. plane is discussed in Section 7.6.
Packet Sequence Number Integrity Considerations Packet Sequence Number Integrity Considerations
The use of PREOF in a DetNet implementation implies the use of a The use of PREOF in a DetNet implementation implies the use of a
sequence number for each packet. There is a trust relationship sequence number for each packet. There is a trust relationship
between the device that adds the sequence number and the device between the device that adds the sequence number and the device
that removes the sequence number. The sequence number may be end- that removes the sequence number. The sequence number may be end-
to-end source to destination, or may be added/deleted by network to-end source to destination, or may be added/deleted by network
edge devices. The adder and remover(s) have the trust edge devices. The adder and remover(s) have the trust
relationship because they are the ones that ensure that the relationship because they are the ones that ensure that the
sequence numbers are not modifiable. Between those two points, sequence numbers are not modifiable. Between those two points,
there may or may not be replication and elimination functions. there may or may not be replication and elimination functions.
The elimination functions must be able to see the sequence The elimination functions must be able to see the sequence
numbers. Therefore any encryption that is done between adders and numbers. Therefore any encryption that is done between adders and
removers must not obscure the sequence number. If the sequence removers must not obscure the sequence number. If the sequence
removers and the eliminators are in the same physical device, it removers and the eliminators are in the same physical device, it
may be possible to obscure the sequence number, however that is a may be possible to obscure the sequence number, however that is a
layer violation, and is not recommended practice. layer violation, and is not recommended practice. Note: At the
time of this writing, PREOF is not defined for the IP data plane.
Related attacks Related attacks
Integrity protection mitigates attacks related to modification and Integrity protection mitigates attacks related to modification and
tampering, including the attacks described in Section 3.2.2 and tampering, including the attacks described in Section 5.2.2 and
Section 3.2.4. Section 5.2.4.
5.3. DetNet Node Authentication 7.3. DetNet Node Authentication
Description Description
Source authentication verifies the authenticity of DetNet sources, Source authentication verifies the authenticity of DetNet sources,
enabling mitigation of spoofing attacks. Note that while enabling mitigation of spoofing attacks. Note that while
integrity protection (Section 5.2) prevents intermediate nodes integrity protection (Section 7.2) prevents intermediate nodes
from modifying information, authentication can provide traffic from modifying information, authentication can provide traffic
origin verification, i.e. to verify that each packet in a DetNet origin verification, i.e. to verify that each packet in a DetNet
flow is from a trusted source. Authentication may be implemented flow is from a trusted source. Authentication may be implemented
as part of ingress filtering, for example. as part of ingress filtering, for example.
Related attacks Related attacks
DetNet node authentication is used to mitigate attacks related to DetNet node authentication is used to mitigate attacks related to
spoofing, including the attacks of Section 3.2.2, and spoofing, including the attacks of Section 5.2.2, and
Section 3.2.4. Section 5.2.4.
5.4. Dummy Traffic Insertion 7.4. Dummy Traffic Insertion
Description Description
With some queueing methods such as [IEEE802.1Qch-2017] it is With some queueing methods such as [IEEE802.1Qch-2017] it is
possible to introduce dummy traffic in order to regularize the possible to introduce dummy traffic in order to regularize the
timing of packet transmission. timing of packet transmission.
Related attacks Related attacks
Removing distinctive temporal properties of individual packets or Removing distinctive temporal properties of individual packets or
flows can be used to mitigate against reconnaissance attacks flows can be used to mitigate against reconnaissance attacks
Section 3.2.7. Section 5.2.7.
5.5. Encryption 7.5. Encryption
Description Description
DetNet flows can in principle be forwarded in encrypted form at DetNet flows can in principle be forwarded in encrypted form at
the DetNet layer, however, regarding encryption of IP headers see the DetNet layer, however, regarding encryption of IP headers see
Section 7. Section 9.
Alternatively, if the payload is end-to-end encrypted at the Alternatively, if the payload is end-to-end encrypted at the
application layer, the DetNet nodes should not have any need to application layer, the DetNet nodes should not have any need to
inspect the payload itself, and thus the DetNet implementation can inspect the payload itself, and thus the DetNet implementation can
be data-agnostic. be data-agnostic.
Encryption can also be applied at the subnet layer, for example Encryption can also be applied at the subnet layer, for example
for Ethernet using MACSec, as noted in Section 7. for Ethernet using MACSec, as noted in Section 9.
Related attacks Related attacks
Encryption can be used to mitigate recon attacks (Section 3.2.7). Encryption can be used to mitigate recon attacks (Section 5.2.7).
However, for a DetNet network to give differentiated quality of However, for a DetNet network to give differentiated quality of
service on a flow-by-flow basis, the network must be able to service on a flow-by-flow basis, the network must be able to
identify the flows individually. This implies that in a recon identify the flows individually. This implies that in a recon
attack the attacker may also be able to track individual flows to attack the attacker may also be able to track individual flows to
learn more about the system. learn more about the system.
5.5.1. Encryption Considerations for DetNet 7.5.1. Encryption Considerations for DetNet
Any compute time which is required for encryption and decryption Any compute time which is required for encryption and decryption
processing ('crypto') must be included in the flow latency processing ('crypto') must be included in the flow latency
calculations. Thus, crypto algorithms used in a DetNet must have calculations. Thus, crypto algorithms used in a DetNet must have
bounded worst-case execution times, and these values must be used in bounded worst-case execution times, and these values must be used in
the latency calculations. the latency calculations.
Some crypto algorithms are symmetric in encode/decode time (such as Some crypto algorithms are symmetric in encode/decode time (such as
AES) and others are asymmetric (such as public key algorithms). AES) and others are asymmetric (such as public key algorithms).
There are advantages and disadvantages to the use of either type in a There are advantages and disadvantages to the use of either type in a
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In either case, origin verification also requires replay detection as In either case, origin verification also requires replay detection as
part of the security protocol to prevent an attacker from recording part of the security protocol to prevent an attacker from recording
and resending traffic, e.g., as a denial of service attack on flow and resending traffic, e.g., as a denial of service attack on flow
forwarding resources. forwarding resources.
If crypto keys are to be regenerated over the duration of the flow If crypto keys are to be regenerated over the duration of the flow
then the time required to accomplish this must be accounted for in then the time required to accomplish this must be accounted for in
the latency calculations. the latency calculations.
5.6. Control and Signaling Message Protection 7.6. Control and Signaling Message Protection
Description Description
Control and sigaling messages can be protected using Control and sigaling messages can be protected using
authentication and integrity protection mechanisms. authentication and integrity protection mechanisms.
Related attacks Related attacks
These mechanisms can be used to mitigate various attacks on the These mechanisms can be used to mitigate various attacks on the
controller plane, as described in Section 3.2.6, Section 3.2.8 and controller plane, as described in Section 5.2.6, Section 5.2.8 and
Section 3.2.5. Section 5.2.5.
5.7. Dynamic Performance Analytics 7.7. Dynamic Performance Analytics
Description Description
The expectation is that the network will have a way to monitor to The expectation is that the network will have a way to monitor to
detect if timing guarantees are not being met, and a way to alert detect if timing guarantees are not being met, and a way to alert
the controller plane in that event. Information about the network the controller plane in that event. Information about the network
performance can be gathered in real-time in order to detect performance can be gathered in real-time in order to detect
anomalies and unusual behavior that may be the symptom of a anomalies and unusual behavior that may be the symptom of a
security attack. The gathered information can be based, for security attack. The gathered information can be based, for
example, on per-flow counters, bandwidth measurement, and example, on per-flow counters, bandwidth measurement, and
monitoring of packet arrival times. Unusual behavior or monitoring of packet arrival times. Unusual behavior or
potentially malicious nodes can be reported to a management potentially malicious nodes can be reported to a management
system, or can be used as a trigger for taking corrective actions. system, or can be used as a trigger for taking corrective actions.
The information can be tracked by DetNet end systems and transit The information can be tracked by DetNet end systems and transit
nodes, and exported to a management system, for example using nodes, and exported to a management system, for example using
YANG. YANG.
Related attacks Related attacks
Performance analytics can be used to mitigate various attacks, Performance analytics can be used to mitigate various attacks,
including the ones described in Section 3.2.1 (Delay Attack), including the ones described in Section 5.2.1 (Delay Attack),
Section 3.2.3 (Resource Segmentation Attack), and Section 3.2.8 Section 5.2.3 (Resource Segmentation Attack), and Section 5.2.8
(Time Sync Attack). (Time Sync Attack).
For example, in the case of data plane delay attacks, one possible For example, in the case of data plane delay attacks, one possible
mitigation is to timestamp the data at the source, and timestamp mitigation is to timestamp the data at the source, and timestamp
it again at the destination, and if the resulting latency exceeds it again at the destination, and if the resulting latency exceeds
the promised bound, discard that data and warn the operator (and/ the promised bound, discard that data and warn the operator (and/
or enter a fail-safe mode). Note that DetNet specifies packet or enter a fail-safe mode). Note that DetNet specifies packet
sequence numbering, however it does not specify use of packet sequence numbering, however it does not specify use of packet
timestamps, although they may be used by the underlying transport timestamps, although they may be used by the underlying transport
(for example TSN) to provide the service. (for example TSN) to provide the service.
5.8. Mitigation Summary 7.8. Mitigation Summary
The following table maps the attacks of Section 3 to the impacts of The following table maps the attacks of Section 5, Security Threats,
Section 4, and to the mitigations of the current section. Each row to the impacts of Section 6, Security Threat Impacts, and to the
specifies an attack, the impact of this attack if it is successfully mitigations of the current section. Each row specifies an attack,
implemented, and possible mitigation methods. the impact of this attack if it is successfully implemented, and
possible mitigation methods.
+----------------------+---------------------+---------------------+ +----------------------+---------------------+---------------------+
| Attack | Impact | Mitigations | | Attack | Impact | Mitigations |
+----------------------+---------------------+---------------------+ +----------------------+---------------------+---------------------+
|Delay Attack |-Non-deterministic |-Path redundancy | |Delay Attack |-Non-deterministic |-Path redundancy |
| | delay |-Performance | | | delay |-Performance |
| |-Data disruption | analytics | | |-Data disruption | analytics |
| |-Increased resource | | | |-Increased resource | |
| | consumption | | | | consumption | |
+----------------------+---------------------+---------------------+ +----------------------+---------------------+---------------------+
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+----------------------+---------------------+---------------------+ +----------------------+---------------------+---------------------+
|Attacks on Time Sync |-Non-deterministic |-Path redundancy | |Attacks on Time Sync |-Non-deterministic |-Path redundancy |
|Mechanisms | delay |-Control message | |Mechanisms | delay |-Control message |
| |-Increased resource | protection | | |-Increased resource | protection |
| | consumption |-Performance | | | consumption |-Performance |
| |-Data disruption | analytics | | |-Data disruption | analytics |
+----------------------+---------------------+---------------------+ +----------------------+---------------------+---------------------+
Figure 3: Mapping Attacks to Impact and Mitigations Figure 3: Mapping Attacks to Impact and Mitigations
6. Association of Attacks to Use Cases 8. Association of Attacks to Use Cases
Different attacks can have different impact and/or mitigation Different attacks can have different impact and/or mitigation
depending on the use case, so we would like to make this association depending on the use case, so we would like to make this association
in our analysis. However since there is a potentially unbounded list in our analysis. However since there is a potentially unbounded list
of use cases, we categorize the attacks with respect to the common of use cases, we categorize the attacks with respect to the common
themes of the use cases as identified in the Use Case Common Themes themes of the use cases as identified in the Use Case Common Themes
section of the DetNet Use Cases [RFC8578]. section of the DetNet Use Cases [RFC8578].
See also Figure 2 for a mapping of the impact of attacks per use case See also Figure 2 for a mapping of the impact of attacks per use case
by industry. by industry.
6.1. Use Cases by Common Themes 8.1. Use Cases by Common Themes
In this section we review each theme and discuss the attacks that are In this section we review each theme and discuss the attacks that are
applicable to that theme, as well as anything specific about the applicable to that theme, as well as anything specific about the
impact and mitigations for that attack with respect to that theme. impact and mitigations for that attack with respect to that theme.
The table Figure 5 then provides a summary of the attacks that are The table Figure 5, Mapping Between Themes and Attacks, then provides
applicable to each theme. a summary of the attacks that are applicable to each theme.
6.1.1. Sub-Network Layer 8.1.1. Sub-Network Layer
DetNet is expected to run over various transmission mediums, with DetNet is expected to run over various transmission mediums, with
Ethernet being the first identified. Attacks such as Delay or Ethernet being the first identified. Attacks such as Delay or
Reconnaissance might be implemented differently on a different Reconnaissance might be implemented differently on a different
transmission medium, however the impact on the DetNet as a whole transmission medium, however the impact on the DetNet as a whole
would be essentially the same. We thus conclude that all attacks and would be essentially the same. We thus conclude that all attacks and
impacts that would be applicable to DetNet over Ethernet (i.e. all impacts that would be applicable to DetNet over Ethernet (i.e. all
those named in this document) would also be applicable to DetNet over those named in this document) would also be applicable to DetNet over
other transmission mediums. other transmission mediums.
With respect to mitigations, some methods are specific to the With respect to mitigations, some methods are specific to the
Ethernet medium, for example time-aware scheduling using 802.1Qbv can Ethernet medium, for example time-aware scheduling using 802.1Qbv can
protect against excessive use of bandwidth at the ingress - for other protect against excessive use of bandwidth at the ingress - for other
mediums, other mitigations would have to be implemented to provide mediums, other mitigations would have to be implemented to provide
analogous protection. analogous protection.
6.1.2. Central Administration 8.1.2. Central Administration
A DetNet network can be controlled by a centralized network A DetNet network can be controlled by a centralized network
configuration and control system. Such a system may be in a single configuration and control system. Such a system may be in a single
central location, or it may be distributed across multiple control central location, or it may be distributed across multiple control
entities that function together as a unified control system for the entities that function together as a unified control system for the
network. network.
In this document we distinguish between attacks on the DetNet In this document we distinguish between attacks on the DetNet
Controller plane vs. Data plane. But is an attack affecting control Controller plane vs. Data plane. But is an attack affecting control
plane packets synonymous with an attack on the control plane itself? plane packets synonymous with an attack on the control plane itself?
For purposes of this document let us consider an attack on the For purposes of this document let us consider an attack on the
control system itself to be out of scope, and consider all attacks control system itself to be out of scope, and consider all attacks
named in this document which are relevant to controller plane packets named in this document which are relevant to controller plane packets
to be relevant to this theme, including Path Manipulation, Path to be relevant to this theme, including Path Manipulation, Path
Choice, Control Packet Modification or Injection, Reconaissance and Choice, Control Packet Modification or Injection, Reconaissance and
Attacks on Time Sync Mechanisms. Attacks on Time Sync Mechanisms.
6.1.3. Hot Swap 8.1.3. Hot Swap
A DetNet network is not expected to be "plug and play" - it is A DetNet network is not expected to be "plug and play" - it is
expected that there is some centralized network configuration and expected that there is some centralized network configuration and
control system. However, the ability to "hot swap" components (e.g. control system. However, the ability to "hot swap" components (e.g.
due to malfunction) is similar enough to "plug and play" that this due to malfunction) is similar enough to "plug and play" that this
kind of behavior may be expected in DetNet networks, depending on the kind of behavior may be expected in DetNet networks, depending on the
implementation. implementation.
An attack surface related to Hot Swap is that the DetNet network must An attack surface related to Hot Swap is that the DetNet network must
at least consider input at runtime from devices that were not part of at least consider input at runtime from devices that were not part of
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of a new device). of a new device).
Similarly if the network was designed to support runtime replacement Similarly if the network was designed to support runtime replacement
of a clock device, then presence (or apparent presence) and thus of a clock device, then presence (or apparent presence) and thus
consideration of packets from a new such device could affect the consideration of packets from a new such device could affect the
network, or the time sync of the network, for example by initiating a network, or the time sync of the network, for example by initiating a
new Best Master Clock selection process. Thus attacks on time sync new Best Master Clock selection process. Thus attacks on time sync
should be considered when designing hot swap type functionality (see should be considered when designing hot swap type functionality (see
[RFC7384]). [RFC7384]).
6.1.4. Data Flow Information Models 8.1.4. Data Flow Information Models
Data Flow YANG models specific to DetNet networks are specified by Data Flow YANG models specific to DetNet networks are specified by
DetNet, and thus are 'new' and thus potentially present a new attack DetNet, and thus are 'new' and thus potentially present a new attack
surface. surface.
6.1.5. L2 and L3 Integration 8.1.5. L2 and L3 Integration
A DetNet network integrates Layer 2 (bridged) networks (e.g. AVB/TSN A DetNet network integrates Layer 2 (bridged) networks (e.g. AVB/TSN
LAN) and Layer 3 (routed) networks via the use of well-known LAN) and Layer 3 (routed) networks via the use of well-known
protocols such as IP, MPLS-PW, and Ethernet. protocols such as IP, MPLS-PW, and Ethernet.
There are no specific entries in our table, however that does not There are no specific entries in our table, however that does not
imply that there could be no relevant attacks related to L2,L3 imply that there could be no relevant attacks related to L2,L3
integration. integration.
6.1.6. End-to-End Delivery 8.1.6. End-to-End Delivery
Packets sent over DetNet are not to be dropped by the network due to Packets sent over DetNet are not to be dropped by the network due to
congestion. (Packets may however intentionally be dropped for congestion. (Packets may however intentionally be dropped for
intended reasons, e.g. per security measures). intended reasons, e.g. per security measures).
A Data plane attack may force packets to be dropped, for example a A Data plane attack may force packets to be dropped, for example a
"long" Delay or Replication/Elimination or Flow Modification attack. "long" Delay or Replication/Elimination or Flow Modification attack.
The same result might be obtained by a controller plane attack, e.g. The same result might be obtained by a controller plane attack, e.g.
Path Manipulation or Signaling Packet Modification. Path Manipulation or Signaling Packet Modification.
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to be preferred over another path when they should not be to be preferred over another path when they should not be
(Replication attack), or by Flow Modification, or by Path Choice or (Replication attack), or by Flow Modification, or by Path Choice or
Packet Injection. A Time Sync attack could cause a system that was Packet Injection. A Time Sync attack could cause a system that was
expecting certain packets at certain times to accept unintended expecting certain packets at certain times to accept unintended
packets based on compromised system time or time windowing in the packets based on compromised system time or time windowing in the
scheduler. scheduler.
Packets may also be dropped due to malfunctioning software or Packets may also be dropped due to malfunctioning software or
hardware. hardware.
6.1.7. Proprietary Deterministic Ethernet Networks 8.1.7. Proprietary Deterministic Ethernet Networks
There are many proprietary non-interoperable deterministic Ethernet- There are many proprietary non-interoperable deterministic Ethernet-
based networks currently available; DetNet is intended to provide an based networks currently available; DetNet is intended to provide an
open-standards-based alternative to such networks. In cases where a open-standards-based alternative to such networks. In cases where a
DetNet intersects with remnants of such networks or their protocols, DetNet intersects with remnants of such networks or their protocols,
such as by protocol emulation or access to such a network via a such as by protocol emulation or access to such a network via a
gateway, new attack surfaces can be opened. gateway, new attack surfaces can be opened.
For example an Inter-Segment or Controller plane attack such as Path For example an Inter-Segment or Controller plane attack such as Path
Manipulation, Path Choice or Control Packet Modification/Injection Manipulation, Path Choice or Control Packet Modification/Injection
could be used to exploit commands specific to such a protocol, or could be used to exploit commands specific to such a protocol, or
that are interpreted differently by the different protocols or that are interpreted differently by the different protocols or
gateway. gateway.
6.1.8. Replacement for Proprietary Fieldbuses 8.1.8. Replacement for Proprietary Fieldbuses
There are many proprietary "field buses" used in today's industrial There are many proprietary "field buses" used in today's industrial
and other industries; DetNet is intended to provide an open- and other industries; DetNet is intended to provide an open-
standards-based alternative to such buses. In cases where a DetNet standards-based alternative to such buses. In cases where a DetNet
intersects with such fieldbuses or their protocols, such as by intersects with such fieldbuses or their protocols, such as by
protocol emulation or access via a gateway, new attack surfaces can protocol emulation or access via a gateway, new attack surfaces can
be opened. be opened.
For example an Inter-Segment or Controller plane attack such as Path For example an Inter-Segment or Controller plane attack such as Path
Manipulation, Path Choice or Control Packet Modification/Injection Manipulation, Path Choice or Control Packet Modification/Injection
could be used to exploit commands specific to such a protocol, or could be used to exploit commands specific to such a protocol, or
that are interpreted differently by the different protocols or that are interpreted differently by the different protocols or
gateway. gateway.
6.1.9. Deterministic vs Best-Effort Traffic 8.1.9. Deterministic vs Best-Effort Traffic
Most of the themes described in this document address OT (reserved) Most of the themes described in this document address OT (reserved)
DetNet flows - this item is intended to address issues related to IT DetNet flows - this item is intended to address issues related to IT
traffic on a DetNet. traffic on a DetNet.
DetNet is intended to support coexistence of time-sensitive DetNet is intended to support coexistence of time-sensitive
operational (OT, deterministic) traffic and information (IT, "best operational (OT, deterministic) traffic and information (IT, "best
effort") traffic on the same ("unified") network. effort") traffic on the same ("unified") network.
With DetNet, this coexistance will become more common, and With DetNet, this coexistance will become more common, and
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with the intent of disrupting handling of IT traffic, and/or the goal with the intent of disrupting handling of IT traffic, and/or the goal
of interfering with OT traffic. Presumably if the DetNet flow of interfering with OT traffic. Presumably if the DetNet flow
reservation and isolation of the DetNet is well-designed (better- reservation and isolation of the DetNet is well-designed (better-
designed than the attack) then interference with OT traffic should designed than the attack) then interference with OT traffic should
not result from an attack that floods the network with IT traffic. not result from an attack that floods the network with IT traffic.
However the DetNet's handling of IT traffic may not (by design) be as However the DetNet's handling of IT traffic may not (by design) be as
resilient to DOS attack, and thus designers must be otherwise resilient to DOS attack, and thus designers must be otherwise
prepared to mitigate DOS attacks on IT traffic in a DetNet. prepared to mitigate DOS attacks on IT traffic in a DetNet.
6.1.10. Deterministic Flows 8.1.10. Deterministic Flows
Reserved bandwidth data flows (deterministic flows) must provide the Reserved bandwidth data flows (deterministic flows) must provide the
allocated bandwidth, and must be isolated from each other. allocated bandwidth, and must be isolated from each other.
A Spoofing or Inter-segment attack which adds packet traffic to a A Spoofing or Inter-segment attack which adds packet traffic to a
bandwidth-reserved DetNet flow could cause that flow to occupy more bandwidth-reserved DetNet flow could cause that flow to occupy more
bandwidth than it was allocated, resulting in interference with other bandwidth than it was allocated, resulting in interference with other
DetNet flows. DetNet flows.
A Flow Modification or Spoofing or Header Manipulation or Control A Flow Modification or Spoofing or Header Manipulation or Control
Packet Modification attack could cause packets from one flow to be Packet Modification attack could cause packets from one flow to be
directed to another flow, thus breaching isolation between the flows. directed to another flow, thus breaching isolation between the flows.
6.1.11. Unused Reserved Bandwidth 8.1.11. Unused Reserved Bandwidth
If bandwidth reservations are made for a DetNet flow but the If bandwidth reservations are made for a DetNet flow but the
associated bandwidth is not used at any point in time, that bandwidth associated bandwidth is not used at any point in time, that bandwidth
is made available on the network for best-effort traffic. However, is made available on the network for best-effort traffic. However,
note that security considerations for best-effort traffic on a DetNet note that security considerations for best-effort traffic on a DetNet
network is out of scope of the present document, provided that such network is out of scope of the present document, provided that such
an attack does not affect performance for DetNet OT traffic. an attack does not affect performance for DetNet OT traffic.
6.1.12. Interoperability 8.1.12. Interoperability
The DetNet network specifications are intended to enable an ecosystem The DetNet network specifications are intended to enable an ecosystem
in which multiple vendors can create interoperable products, thus in which multiple vendors can create interoperable products, thus
promoting device diversity and potentially higher numbers of each promoting device diversity and potentially higher numbers of each
device manufactured. device manufactured.
Given that the DetNet specifications are unambiguously written and Given that the DetNet specifications are unambiguously written and
that the implementations are accurate, then this should not in and of that the implementations are accurate, then this should not in and of
itself cause a security concern; however, in the real world, it could itself cause a security concern; however, in the real world, it could
be. The network operator can mitigate this through sufficient be. The network operator can mitigate this through sufficient
interoperability testing. interoperability testing.
6.1.13. Cost Reductions 8.1.13. Cost Reductions
The DetNet network specifications are intended to enable an ecosystem The DetNet network specifications are intended to enable an ecosystem
in which multiple vendors can create interoperable products, thus in which multiple vendors can create interoperable products, thus
promoting higher numbers of each device manufactured, promoting cost promoting higher numbers of each device manufactured, promoting cost
reduction and cost competition among vendors. Such "low cost" reduction and cost competition among vendors. Such "low cost"
hardware or software components might present security concerns. hardware or software components might present security concerns.
Network operators can mitigate such concerns through sufficient Network operators can mitigate such concerns through sufficient
product testing. product testing.
6.1.14. Insufficiently Secure Devices 8.1.14. Insufficiently Secure Devices
The DetNet network specifications are intended to enable an ecosystem The DetNet network specifications are intended to enable an ecosystem
in which multiple vendors can create interoperable products, thus in which multiple vendors can create interoperable products, thus
promoting device diversity and potentially higher numbers of each promoting device diversity and potentially higher numbers of each
device manufactured. Software that was originally designed for device manufactured. Software that was originally designed for
operation in isolated OT networks (and thus may not have been operation in isolated OT networks (and thus may not have been
designed to be sufficiently secure, or secure at all) but is then designed to be sufficiently secure, or secure at all) but is then
deployed on a DetNet network that is intended to be highly secure may deployed on a DetNet network that is intended to be highly secure may
present an attack surface. (For example IoT exploits like the Mirai present an attack surface. (For example IoT exploits like the Mirai
video-camera botnet ([MIRAI]). video-camera botnet ([MIRAI]).
The DetNet network operator may need to take specific actions to The DetNet network operator may need to take specific actions to
protect such devices. protect such devices.
6.1.15. DetNet Network Size 8.1.15. DetNet Network Size
DetNet networks range in size from very small, e.g. inside a single DetNet networks range in size from very small, e.g. inside a single
industrial machine, to very large, for example a Utility Grid network industrial machine, to very large, for example a Utility Grid network
spanning a whole country. spanning a whole country.
The size of the network might be related to how the attack is The size of the network might be related to how the attack is
introduced into the network, for example if the entire network is introduced into the network, for example if the entire network is
local, there is a threat that power can be cut to the entire network. local, there is a threat that power can be cut to the entire network.
If the network is large, perhaps only a part of the network is If the network is large, perhaps only a part of the network is
attacked. attacked.
A Delay attack might be as relevant to a small network as to a large A Delay attack might be as relevant to a small network as to a large
network, although the amount of delay might be different. network, although the amount of delay might be different.
Attacks sourced from IT traffic might be more likely in large Attacks sourced from IT traffic might be more likely in large
networks, since more people might have access to the network, networks, since more people might have access to the network,
presenting a larger attack surface. Similarly Path Manipulation, presenting a larger attack surface. Similarly Path Manipulation,
Path Choice and Time Sync attacks seem more likely relevant to large Path Choice and Time Sync attacks seem more likely relevant to large
networks. networks.
6.1.16. Multiple Hops 8.1.16. Multiple Hops
Large DetNet networks (e.g. a Utility Grid network) may involve many Large DetNet networks (e.g. a Utility Grid network) may involve many
"hops" over various kinds of links for example radio repeaters, "hops" over various kinds of links for example radio repeaters,
microwave links, fiber optic links, etc.. microwave links, fiber optic links, etc.
An attack that takes advantage of flaws (or even normal operation) in An attack that takes advantage of flaws (or even normal operation) in
the device drivers for the various links (through internal knowledge the device drivers for the various links (through internal knowledge
of how the individual driver or firmware operates, perhaps like the of how the individual driver or firmware operates, perhaps like the
Stuxnet attack) could take proportionately greater advantage of this Stuxnet attack) could take proportionately greater advantage of this
topology. We don't currently have an attack like this defined; we topology.
have only "protocol" (time or packet) based attacks. Perhaps we need
to define an attack like this? Or is that out of scope for DetNet?
It is also possible that this DetNet topology will not be in as It is also possible that this DetNet topology will not be in as
common use as other more homogeneous topologies so there may be more common use as other more homogeneous topologies so there may be more
opportunity for attackers to exploit software and/or protocol flaws opportunity for attackers to exploit software and/or protocol flaws
in the implementations which have not been wrung out by extensive in the implementations which have not been wrung out by extensive
use, particularly in the case of early adopters. use, particularly in the case of early adopters.
Of the attacks we have defined, the ones identified above as relevant Of the attacks we have defined, the ones identified above as relevant
to "large" networks seem to be most relevant. to "large" networks are the most relevant.
6.1.17. Level of Service 8.1.17. Level of Service
A DetNet is expected to provide means to configure the network that A DetNet is expected to provide means to configure the network that
include querying network path latency, requesting bounded latency for include querying network path latency, requesting bounded latency for
a given DetNet flow, requesting worst case maximum and/or minimum a given DetNet flow, requesting worst case maximum and/or minimum
latency for a given path or DetNet flow, and so on. It is an latency for a given path or DetNet flow, and so on. It is an
expected case that the network cannot provide a given requested expected case that the network cannot provide a given requested
service level. In such cases the network control system should reply service level. In such cases the network control system should reply
that the requested service level is not available (as opposed to that the requested service level is not available (as opposed to
accepting the parameter but then not delivering the desired accepting the parameter but then not delivering the desired
behavior). behavior).
Controller plane attacks such as Signaling Packet Modification and Controller plane attacks such as Signaling Packet Modification and
Injection could be used to modify or create control traffic that Injection could be used to modify or create control traffic that
could interfere with the process of a user requesting a level of could interfere with the process of a user requesting a level of
service and/or the network's reply. service and/or the network's reply.
Reconnaissance could be used to characterize flows and perhaps target Reconnaissance could be used to characterize flows and perhaps target
specific flows for attack via the controller plane as noted above. specific flows for attack via the controller plane as noted above.
6.1.18. Bounded Latency 8.1.18. Bounded Latency
DetNet provides the expectation of guaranteed bounded latency. DetNet provides the expectation of guaranteed bounded latency.
Delay attacks can cause packets to miss their agreed-upon latency Delay attacks can cause packets to miss their agreed-upon latency
boundaries. boundaries.
Time Sync attacks can corrupt the system's time reference, resulting Time Sync attacks can corrupt the system's time reference, resulting
in missed latency deadlines (with respect to the "correct" time in missed latency deadlines (with respect to the "correct" time
reference). reference).
6.1.19. Low Latency 8.1.19. Low Latency
Applications may require "extremely low latency" however depending on Applications may require "extremely low latency" however depending on
the application these may mean very different latency values; for the application these may mean very different latency values; for
example "low latency" across a Utility grid network is on a different example "low latency" across a Utility grid network is on a different
time scale than "low latency" in a motor control loop in a small time scale than "low latency" in a motor control loop in a small
machine. The intent is that the mechanisms for specifying desired machine. The intent is that the mechanisms for specifying desired
latency include wide ranges, and that architecturally there is latency include wide ranges, and that architecturally there is
nothing to prevent arbitrarily low latencies from being implemented nothing to prevent arbitrarily low latencies from being implemented
in a given network. in a given network.
Attacks on the controller plane (as described in the Level of Service Attacks on the controller plane (as described in the Level of Service
theme) and Delay and Time attacks (as described in the Bounded theme) and Delay and Time attacks (as described in the Bounded
Latency theme) both apply here. Latency theme) both apply here.
6.1.20. Bounded Jitter (Latency Variation) 8.1.20. Bounded Jitter (Latency Variation)
DetNet is expected to provide bounded jitter (packet to packet DetNet is expected to provide bounded jitter (packet to packet
latency variation). latency variation).
Delay attacks can cause packets to vary in their arrival times, Delay attacks can cause packets to vary in their arrival times,
resulting in packet to packet latency variation, thereby violating resulting in packet to packet latency variation, thereby violating
the jitter specification. the jitter specification.
6.1.21. Symmetrical Path Delays 8.1.21. Symmetrical Path Delays
Some applications would like to specify that the transit delay time Some applications would like to specify that the transit delay time
values be equal for both the transmit and return paths. values be equal for both the transmit and return paths.
Delay attacks can cause path delays to materially differ between Delay attacks can cause path delays to materially differ between
paths. paths.
Time Sync attacks can corrupt the system's time reference, resulting Time Sync attacks can corrupt the system's time reference, resulting
in path delays that may be perceived to be different (with respect to in path delays that may be perceived to be different (with respect to
the "correct" time reference) even if they are not materially the "correct" time reference) even if they are not materially
different. different.
6.1.22. Reliability and Availability 8.1.22. Reliability and Availability
DetNet based systems are expected to be implemented with essentially DetNet based systems are expected to be implemented with essentially
arbitrarily high availability (for example 99.9999% up time, or even arbitrarily high availability (for example 99.9999% up time, or even
12 nines). The intent is that the DetNet designs should not make any 12 nines). The intent is that the DetNet designs should not make any
assumptions about the level of reliability and availability that may assumptions about the level of reliability and availability that may
be required of a given system, and should define parameters for be required of a given system, and should define parameters for
communicating these kinds of metrics within the network. communicating these kinds of metrics within the network.
Any attack on the system, of any type, can affect its overall Any attack on the system, of any type, can affect its overall
reliability and availability, thus in our table we have marked every reliability and availability, thus in our table we have marked every
attack. Since every DetNet depends to a greater or lesser degree on attack. Since every DetNet depends to a greater or lesser degree on
reliability and availability, this essentially means that all reliability and availability, this essentially means that all
networks have to mitigate all attacks, which to a greater or lesser networks have to mitigate all attacks, which to a greater or lesser
degree defeats the purpose of associating attacks with use cases. It degree defeats the purpose of associating attacks with use cases. It
also underscores the difficulty of designing "extremely high also underscores the difficulty of designing "extremely high
reliability" networks. reliability" networks.
6.1.23. Redundant Paths 8.1.23. Redundant Paths
DetNet based systems are expected to be implemented with essentially DetNet based systems are expected to be implemented with essentially
arbitrarily high reliability/availability. A strategy used by DetNet arbitrarily high reliability/availability. A strategy used by DetNet
for providing such extraordinarily high levels of reliability is to for providing such extraordinarily high levels of reliability is to
provide redundant paths that can be seamlessly switched between, all provide redundant paths that can be seamlessly switched between, all
the while maintaining the required performance of that system. the while maintaining the required performance of that system.
Replication-related attacks are by definition applicable here. Replication-related attacks are by definition applicable here.
Controller plane attacks can also interfere with the configuration of Controller plane attacks can also interfere with the configuration of
redundant paths. redundant paths.
6.1.24. Security Measures 8.1.24. Security Measures
A DetNet network must be made secure against devices failures, A DetNet network must be made secure against devices failures,
attackers, misbehaving devices, and so on. Does the threat affect attackers, misbehaving devices, and so on. Does the threat affect
such security measures themselves, e.g. by attacking SW designed to such security measures themselves, e.g. by attacking SW designed to
protect against device failure? protect against device failure?
This is TBD, thus there are no specific entries in our table, however This is TBD, thus there are no specific entries in our table, however
that does not imply that there could be no relevant attacks. that does not imply that there could be no relevant attacks.
6.2. Attack Types by Use Case Common Theme 8.2. Attack Types by Use Case Common Theme
The following table lists the attacks of Section 3, assigning a The following table lists the attacks of Section 5, Security Threats,
number to each type of attack. That number is then used as a short assigning a number to each type of attack. That number is then used
form identifier for the attack in Figure 5. as a short form identifier for the attack in Figure 5, Mapping
Between Themes and Attacks.
+--+----------------------------------------+----------------------+ +--+----------------------------------------+----------------------+
| | Attack | Section | | | Attack | Section |
+--+----------------------------------------+----------------------+ +--+----------------------------------------+----------------------+
| 1|Delay Attack | Section 3.2.1 | | 1|Delay Attack | Section 3.2.1 |
+--+----------------------------------------+----------------------+ +--+----------------------------------------+----------------------+
| 2|DetNet Flow Modification or Spoofing | Section 3.2.2 | | 2|DetNet Flow Modification or Spoofing | Section 3.2.2 |
+--+----------------------------------------+----------------------+ +--+----------------------------------------+----------------------+
| 3|Inter-Segment Attack | Section 3.2.3 | | 3|Inter-Segment Attack | Section 3.2.3 |
+--+----------------------------------------+----------------------+ +--+----------------------------------------+----------------------+
skipping to change at page 34, line 5 skipping to change at page 38, line 5
+----------------------------+--+--+--+--+--+--+--+--+--+--+--+ +----------------------------+--+--+--+--+--+--+--+--+--+--+--+
|Reliability and Availability| +| +| +| +| +| +| +| +| +| +| +| |Reliability and Availability| +| +| +| +| +| +| +| +| +| +| +|
+----------------------------+--+--+--+--+--+--+--+--+--+--+--+ +----------------------------+--+--+--+--+--+--+--+--+--+--+--+
|Redundant Paths | | | | +| +| | | +| +| | | |Redundant Paths | | | | +| +| | | +| +| | |
+----------------------------+--+--+--+--+--+--+--+--+--+--+--+ +----------------------------+--+--+--+--+--+--+--+--+--+--+--+
|Security Measures | | | | | | | | | | | | |Security Measures | | | | | | | | | | | |
+----------------------------+--+--+--+--+--+--+--+--+--+--+--+ +----------------------------+--+--+--+--+--+--+--+--+--+--+--+
Figure 5: Mapping Between Themes and Attacks Figure 5: Mapping Between Themes and Attacks
6.3. Security Considerations for OAM Traffic 8.3. Security Considerations for OAM Traffic
This section considers DetNet-specific security considerations for This section considers DetNet-specific security considerations for
packet traffic that is generated and transmitted over a DetNet as packet traffic that is generated and transmitted over a DetNet as
part of OAM (Operations, Administration and Maintenance). For part of OAM (Operations, Administration and Maintenance). For
purposes of this discussion, OAM traffic falls into one of two basic purposes of this discussion, OAM traffic falls into one of two basic
types: types:
o OAM traffic generated by the network itself. The additional o OAM traffic generated by the network itself. The additional
bandwidth required for such packets is added by the network bandwidth required for such packets is added by the network
administration, presumably transparent to the customer. Security administration, presumably transparent to the customer. Security
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security considerations as any other DetNet data flow) and are security considerations as any other DetNet data flow) and are
thus not covered in this document. thus not covered in this document.
o OAM traffic generated by the customer. From a DetNet security o OAM traffic generated by the customer. From a DetNet security
point of view, DetNet security considerations for such traffic are point of view, DetNet security considerations for such traffic are
exactly the same as for any other customer data flows. exactly the same as for any other customer data flows.
Thus OAM traffic presents no additional (i.e. OAM-specific) DetNet Thus OAM traffic presents no additional (i.e. OAM-specific) DetNet
security considerations. security considerations.
7. DetNet Technology-Specific Threats 9. DetNet Technology-Specific Threats
Section 3 described threats which are independent of a DetNet Section 5, Security Threats, described threats which are independent
implementation. This section considers threats specifically related of a DetNet implementation. This section considers threats
to the IP- and MPLS-specific aspects of DetNet implementations. specifically related to the IP- and MPLS-specific aspects of DetNet
implementations.
The primary security considerations for the data plane specifically The primary security considerations for the data plane specifically
are to maintain the integrity of the data and the delivery of the are to maintain the integrity of the data and the delivery of the
associated DetNet service traversing the DetNet network. associated DetNet service traversing the DetNet network.
The primary relevant differences between IP and MPLS implementations The primary relevant differences between IP and MPLS implementations
are in flow identification and OAM methodologies. are in flow identification and OAM methodologies.
As noted in [RFC8655], DetNet operates at the IP layer As noted in [RFC8655], DetNet operates at the IP layer
([I-D.ietf-detnet-ip]) and delivers service over sub-layer ([I-D.ietf-detnet-ip]) and delivers service over sub-layer
skipping to change at page 35, line 16 skipping to change at page 39, line 19
DSCP in the IP header. When IPsec is used, the transport header is DSCP in the IP header. When IPsec is used, the transport header is
encrypted and the next protocol ID is an IPsec protocol, usually ESP, encrypted and the next protocol ID is an IPsec protocol, usually ESP,
and not a transport protocol (e.g., neither TCP nor UDP, etc.) and not a transport protocol (e.g., neither TCP nor UDP, etc.)
leaving only three components of the 6-tuple, which are the two IP leaving only three components of the 6-tuple, which are the two IP
addresses and the DSCP, which are in general not sufficient to addresses and the DSCP, which are in general not sufficient to
identify a DetNet flow. identify a DetNet flow.
Sections below discuss threats specific to IP and MPLS in more Sections below discuss threats specific to IP and MPLS in more
detail. detail.
7.1. IP 9.1. IP
The IP protocol has a long history of security considerations and The IP protocol has a long history of security considerations and
architectural protection mechanisms. From a data plane perspective architectural protection mechanisms. From a data plane perspective
DetNet does not add or modify any IP header information, and its use DetNet does not add or modify any IP header information, and its use
as a DetNet Data Plane does not introduce any new security issues as a DetNet Data Plane does not introduce any new security issues
that were not there before, apart from those already described in the that were not there before, apart from those already described in the
data-plane-independent threats section Section 3. data-plane-independent threats section Section 5, Security Threats.
Thus the security considerations for a DetNet based on an IP data Thus the security considerations for a DetNet based on an IP data
plane are purely inherited from the rich IP Security literature and plane are purely inherited from the rich IP Security literature and
code/application base, and the data-plane-independent section of this code/application base, and the data-plane-independent section of this
document. document.
Maintaining security for IP segments of a DetNet may be more Maintaining security for IP segments of a DetNet may be more
challenging than for the MPLS segments of the network, given that the challenging than for the MPLS segments of the network, given that the
IP segments of the network may reach the edges of the network, which IP segments of the network may reach the edges of the network, which
are more likely to involve interaction with potentially malevolent are more likely to involve interaction with potentially malevolent
skipping to change at page 36, line 7 skipping to change at page 40, line 10
isolation between flows, for example by protecting the forwarding isolation between flows, for example by protecting the forwarding
bandwidth and related resources so that they are available to detnet bandwidth and related resources so that they are available to detnet
traffic, by whatever means are appropriate for that network's data traffic, by whatever means are appropriate for that network's data
plane. plane.
In a VPN, bandwidth is generally guaranteed over a period of time, In a VPN, bandwidth is generally guaranteed over a period of time,
whereas in DetNet it is not aggregated over time. This implies that whereas in DetNet it is not aggregated over time. This implies that
any VPN-type protection mechanism must also maintain the DetNet any VPN-type protection mechanism must also maintain the DetNet
timing constraints. timing constraints.
7.2. MPLS 9.2. MPLS
An MPLS network carrying DetNet traffic is expected to be a "well- An MPLS network carrying DetNet traffic is expected to be a "well-
managed" network. Given that this is the case, it is difficult for managed" network. Given that this is the case, it is difficult for
an attacker to pass a raw MPLS encoded packet into a network because an attacker to pass a raw MPLS encoded packet into a network because
operators have considerable experience at excluding such packets at operators have considerable experience at excluding such packets at
the network boundaries, as well as excluding MPLS packets being the network boundaries, as well as excluding MPLS packets being
inserted through the use of a tunnel. inserted through the use of a tunnel.
MPLS security is discussed extensively in [RFC5920] ("Security MPLS security is discussed extensively in [RFC5920] ("Security
Framework for MPLS and GMPLS Networks") to which the reader is Framework for MPLS and GMPLS Networks") to which the reader is
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One particular problem that has been observed in operational tests of One particular problem that has been observed in operational tests of
TWTT protocols is the ability for two closely but not completely TWTT protocols is the ability for two closely but not completely
synchronized flows to beat and cause a sudden phase hit to one of the synchronized flows to beat and cause a sudden phase hit to one of the
flows. This can be mitigated by the careful use of a scheduling flows. This can be mitigated by the careful use of a scheduling
system in the underlying packet transport. system in the underlying packet transport.
Further consideration of protection against dynamic attacks is work Further consideration of protection against dynamic attacks is work
in progress. in progress.
8. IANA Considerations 10. IANA Considerations
This memo includes no requests from IANA. This memo includes no requests from IANA.
9. Security Considerations 11. Security Considerations
The security considerations of DetNet networks are presented The security considerations of DetNet networks are presented
throughout this document. throughout this document.
10. Contributors 12. Contributors
The Editor would like to recognize the contributions of the following The Editor would like to recognize the contributions of the following
individuals to this draft. individuals to this draft.
Andrew J. Hacker (MistIQ Technologies, Inc) Andrew J. Hacker (MistIQ Technologies, Inc)
Harrisburg, PA, USA Harrisburg, PA, USA
email ajhacker@mistiqtech.com, email ajhacker@mistiqtech.com,
web http://www.mistiqtech.com web http://www.mistiqtech.com
Subir Das (Applied Communication Sciences) Subir Das (Applied Communication Sciences)
skipping to change at page 37, line 40 skipping to change at page 42, line 26
Celtic Springs, Newport, NP10 8FZ, United Kingdom Celtic Springs, Newport, NP10 8FZ, United Kingdom
email john.dowdell.ietf@gmail.com email john.dowdell.ietf@gmail.com
Henrik Austad (SINTEF Digital) Henrik Austad (SINTEF Digital)
Klaebuveien 153, Trondheim, 7037, Norway Klaebuveien 153, Trondheim, 7037, Norway
email henrik@austad.us email henrik@austad.us
Norman Finn Norman Finn
email nfinn@nfinnconsulting.com email nfinn@nfinnconsulting.com
Stewart Bryant
Futurewei Technologies
email: stewart.bryant@gmail.com
David Black
Dell EMC
176 South Street, Hopkinton, MA 01748, USA
email: david.black@dell.com
Carsten Bormann Carsten Bormann
11. Informative References 13. Informative References
[ARINC664P7] [ARINC664P7]
ARINC, "ARINC 664 Aircraft Data Network, Part 7, Avionics ARINC, "ARINC 664 Aircraft Data Network, Part 7, Avionics
Full-Duplex Switched Ethernet Network", 2009. Full-Duplex Switched Ethernet Network", 2009.
[I-D.ietf-detnet-data-plane-framework] [I-D.ietf-detnet-data-plane-framework]
Varga, B., Farkas, J., Berger, L., Malis, A., and S. Varga, B., Farkas, J., Berger, L., Malis, A., and S.
Bryant, "DetNet Data Plane Framework", draft-ietf-detnet- Bryant, "DetNet Data Plane Framework", draft-ietf-detnet-
data-plane-framework-04 (work in progress), February 2020. data-plane-framework-06 (work in progress), May 2020.
[I-D.ietf-detnet-flow-information-model] [I-D.ietf-detnet-flow-information-model]
Farkas, J., Varga, B., Cummings, R., Jiang, Y., and D. Varga, B., Farkas, J., Cummings, R., Jiang, Y., and D.
Fedyk, "DetNet Flow Information Model", draft-ietf-detnet- Fedyk, "DetNet Flow Information Model", draft-ietf-detnet-
flow-information-model-07 (work in progress), March 2020. flow-information-model-10 (work in progress), May 2020.
[I-D.ietf-detnet-ip] [I-D.ietf-detnet-ip]
Varga, B., Farkas, J., Berger, L., Fedyk, D., Malis, A., Varga, B., Farkas, J., Berger, L., Fedyk, D., and S.
and S. Bryant, "DetNet Data Plane: IP", draft-ietf-detnet- Bryant, "DetNet Data Plane: IP", draft-ietf-detnet-ip-06
ip-05 (work in progress), February 2020. (work in progress), April 2020.
[I-D.ietf-detnet-ip-over-tsn] [I-D.ietf-detnet-ip-over-tsn]
Varga, B., Farkas, J., Malis, A., and S. Bryant, "DetNet Varga, B., Farkas, J., Malis, A., and S. Bryant, "DetNet
Data Plane: IP over IEEE 802.1 Time Sensitive Networking Data Plane: IP over IEEE 802.1 Time Sensitive Networking
(TSN)", draft-ietf-detnet-ip-over-tsn-02 (work in (TSN)", draft-ietf-detnet-ip-over-tsn-02 (work in
progress), March 2020. progress), March 2020.
[I-D.ietf-detnet-mpls] [I-D.ietf-detnet-mpls]
Varga, B., Farkas, J., Berger, L., Fedyk, D., Malis, A., Varga, B., Farkas, J., Berger, L., Malis, A., Bryant, S.,
Bryant, S., and J. Korhonen, "DetNet Data Plane: MPLS", and J. Korhonen, "DetNet Data Plane: MPLS", draft-ietf-
draft-ietf-detnet-mpls-05 (work in progress), February detnet-mpls-06 (work in progress), April 2020.
2020.
[I-D.varga-detnet-service-model] [I-D.varga-detnet-service-model]
Varga, B. and J. Farkas, "DetNet Service Model", draft- Varga, B. and J. Farkas, "DetNet Service Model", draft-
varga-detnet-service-model-02 (work in progress), May varga-detnet-service-model-02 (work in progress), May
2017. 2017.
[IEEE1588] [IEEE1588]
IEEE, "IEEE 1588 Standard for a Precision Clock IEEE, "IEEE 1588 Standard for a Precision Clock
Synchronization Protocol for Networked Measurement and Synchronization Protocol for Networked Measurement and
Control Systems Version 2", 2008. Control Systems Version 2", 2008.
skipping to change at page 39, line 9 skipping to change at page 43, line 46
[IEEE802.1Qch-2017] [IEEE802.1Qch-2017]
IEEE Standards Association, "IEEE Standard for Local and IEEE Standards Association, "IEEE Standard for Local and
metropolitan area networks--Bridges and Bridged Networks-- metropolitan area networks--Bridges and Bridged Networks--
Amendment 29: Cyclic Queuing and Forwarding", 2017, Amendment 29: Cyclic Queuing and Forwarding", 2017,
<https://ieeexplore.ieee.org/document/7961303>. <https://ieeexplore.ieee.org/document/7961303>.
[MIRAI] krebsonsecurity.com, "https://krebsonsecurity.com/2016/10/ [MIRAI] krebsonsecurity.com, "https://krebsonsecurity.com/2016/10/
hacked-cameras-dvrs-powered-todays-massive-internet- hacked-cameras-dvrs-powered-todays-massive-internet-
outage/", 2016. outage/", 2016.
[RFC2474] Nichols, K., Blake, S., Baker, F., and D. Black,
"Definition of the Differentiated Services Field (DS
Field) in the IPv4 and IPv6 Headers", RFC 2474,
DOI 10.17487/RFC2474, December 1998,
<https://www.rfc-editor.org/info/rfc2474>.
[RFC2475] Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z.,
and W. Weiss, "An Architecture for Differentiated
Services", RFC 2475, DOI 10.17487/RFC2475, December 1998,
<https://www.rfc-editor.org/info/rfc2475>.
[RFC3552] Rescorla, E. and B. Korver, "Guidelines for Writing RFC [RFC3552] Rescorla, E. and B. Korver, "Guidelines for Writing RFC
Text on Security Considerations", BCP 72, RFC 3552, Text on Security Considerations", BCP 72, RFC 3552,
DOI 10.17487/RFC3552, July 2003, DOI 10.17487/RFC3552, July 2003,
<https://www.rfc-editor.org/info/rfc3552>. <https://www.rfc-editor.org/info/rfc3552>.
[RFC3931] Lau, J., Ed., Townsley, M., Ed., and I. Goyret, Ed., [RFC3931] Lau, J., Ed., Townsley, M., Ed., and I. Goyret, Ed.,
"Layer Two Tunneling Protocol - Version 3 (L2TPv3)", "Layer Two Tunneling Protocol - Version 3 (L2TPv3)",
RFC 3931, DOI 10.17487/RFC3931, March 2005, RFC 3931, DOI 10.17487/RFC3931, March 2005,
<https://www.rfc-editor.org/info/rfc3931>. <https://www.rfc-editor.org/info/rfc3931>.
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