draft-ietf-ospf-ttz-05.txt   draft-ietf-ospf-ttz-06.txt 
Internet Engineering Task Force H. Chen Internet Engineering Task Force H. Chen
Internet-Draft R. Li Internet-Draft R. Li
Intended status: Experimental Huawei Technologies Intended status: Experimental Huawei Technologies
Expires: June 16, 2017 A. Retana Expires: July 12, 2017 A. Retana
Cisco Systems, Inc. Cisco Systems, Inc.
Y. Yang Y. Yang
Sockrate
V. Liu Z. Liu
China Mobile China Mobile
M. Toy January 8, 2017
Verizon
December 13, 2016
OSPF Topology-Transparent Zone OSPF Topology-Transparent Zone
draft-ietf-ospf-ttz-05.txt draft-ietf-ospf-ttz-06.txt
Abstract Abstract
This document presents a topology-transparent zone in an OSPF area. This document presents a topology-transparent zone (TTZ) in an OSPF
A topology-transparent zone comprises a group of routers and a number area. A topology-transparent zone comprises a group of routers and a
of links connecting these routers. Any router outside of the zone is number of links connecting these routers. Any router outside of the
not aware of the zone. The information about the links and routers zone is not aware of the zone. A TTZ hides the internal topology of
such as a link down inside the zone is not advertised to any router the TTZ from the outside. It does not directly advertise any
outside of the zone. internal information about the TTZ to a router outside of the TTZ.
The information about the links and routers such as a link down
inside the TTZ is not advertised to any router outside of the TTZ.
Status of this Memo Status of this Memo
This Internet-Draft is submitted to IETF in full conformance with the This Internet-Draft is submitted to IETF in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on June 16, 2017. This Internet-Draft will expire on July 12, 2017.
Copyright Notice Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
skipping to change at page 3, line 14 skipping to change at page 3, line 14
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Conventions Used in This Document . . . . . . . . . . . . . . 5 3. Conventions Used in This Document . . . . . . . . . . . . . . 5
4. Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 5 4. Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 5
5. Topology-Transparent Zone . . . . . . . . . . . . . . . . . . 5 5. Topology-Transparent Zone . . . . . . . . . . . . . . . . . . 5
5.1. Overview of Topology-Transparent Zone . . . . . . . . . . 5 5.1. Overview of Topology-Transparent Zone . . . . . . . . . . 5
5.2. TTZ Example . . . . . . . . . . . . . . . . . . . . . . . 6 5.2. TTZ Example . . . . . . . . . . . . . . . . . . . . . . . 6
6. Extensions to OSPF Protocols . . . . . . . . . . . . . . . . . 7 6. Extensions to OSPF Protocols . . . . . . . . . . . . . . . . . 8
6.1. General Format of TTZ LSA . . . . . . . . . . . . . . . . 8 6.1. General Format of TTZ LSA . . . . . . . . . . . . . . . . 8
6.2. TTZ ID TLV . . . . . . . . . . . . . . . . . . . . . . . . 9 6.2. TTZ ID TLV . . . . . . . . . . . . . . . . . . . . . . . . 9
6.3. TTZ Router TLV . . . . . . . . . . . . . . . . . . . . . . 9 6.3. TTZ Router TLV . . . . . . . . . . . . . . . . . . . . . . 9
6.4. TTZ Options TLV . . . . . . . . . . . . . . . . . . . . . 10 6.4. TTZ Options TLV . . . . . . . . . . . . . . . . . . . . . 10
6.5. Link Scope TTZ LSA . . . . . . . . . . . . . . . . . . . . 11 6.5. Link Scope TTZ LSA . . . . . . . . . . . . . . . . . . . . 11
7. Constructing LSAs for TTZ . . . . . . . . . . . . . . . . . . 12 7. Constructing LSAs for TTZ . . . . . . . . . . . . . . . . . . 12
7.1. TTZ Migration Process . . . . . . . . . . . . . . . . . . 13 7.1. TTZ Migration Process . . . . . . . . . . . . . . . . . . 13
8. Establishing Adjacencies . . . . . . . . . . . . . . . . . . . 14 8. Establishing Adjacencies . . . . . . . . . . . . . . . . . . . 14
8.1. Discovery of TTZ Neighbors . . . . . . . . . . . . . . . . 14 8.1. Discovery of TTZ Neighbors . . . . . . . . . . . . . . . . 14
8.2. Adjacency between TTZ Edge and TTZ External Router . . . . 17 8.2. Adjacency between TTZ Edge and TTZ External Router . . . . 17
skipping to change at page 3, line 40 skipping to change at page 3, line 40
11.1. Configuring TTZ . . . . . . . . . . . . . . . . . . . . . 18 11.1. Configuring TTZ . . . . . . . . . . . . . . . . . . . . . 18
11.2. Migration to TTZ . . . . . . . . . . . . . . . . . . . . . 19 11.2. Migration to TTZ . . . . . . . . . . . . . . . . . . . . . 19
11.3. Adding a Router into TTZ . . . . . . . . . . . . . . . . . 21 11.3. Adding a Router into TTZ . . . . . . . . . . . . . . . . . 21
12. Manageability Considerations . . . . . . . . . . . . . . . . . 22 12. Manageability Considerations . . . . . . . . . . . . . . . . . 22
13. Security Considerations . . . . . . . . . . . . . . . . . . . 22 13. Security Considerations . . . . . . . . . . . . . . . . . . . 22
14. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22 14. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22
15. Contributors and Other Authors . . . . . . . . . . . . . . . . 23 15. Contributors and Other Authors . . . . . . . . . . . . . . . . 23
16. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 24 16. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 24
17. References . . . . . . . . . . . . . . . . . . . . . . . . . . 24 17. References . . . . . . . . . . . . . . . . . . . . . . . . . . 24
17.1. Normative References . . . . . . . . . . . . . . . . . . . 24 17.1. Normative References . . . . . . . . . . . . . . . . . . . 24
17.2. Informative References . . . . . . . . . . . . . . . . . . 24 17.2. Informative References . . . . . . . . . . . . . . . . . . 25
Appendix A. Prototype Implementation . . . . . . . . . . . . . . 25 Appendix A. Prototype Implementation . . . . . . . . . . . . . . 25
A.1. What are Implemented and Tested . . . . . . . . . . . . . 25 A.1. What are Implemented and Tested . . . . . . . . . . . . . 25
A.2. Implementation Experience . . . . . . . . . . . . . . . . 26 A.2. Implementation Experience . . . . . . . . . . . . . . . . 26
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 26 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 27
1. Introduction 1. Introduction
Networks expand as business grows and traffic increases. For Networks expand as business grows and traffic increases. For
scalability and manageability, a hierarchical network architecture is scalability and manageability, a hierarchical network architecture is
usually deployed in OSPF networks by re-grouping routers into areas, usually deployed in OSPF networks by re-grouping routers into areas,
which is often challenging and causes service interruptions. which is often challenging and causes service interruptions.
At first, reorganizing a network from one area into multiple areas or At first, reorganizing a network from one area into multiple areas or
from a number of existing areas into even more areas is a very from a number of existing areas into even more areas is a very
skipping to change at page 4, line 35 skipping to change at page 4, line 35
routing. routing.
Secondly, the services carried by the network may be interrupted Secondly, the services carried by the network may be interrupted
while the network is being reorganized from one area into multiple while the network is being reorganized from one area into multiple
areas or from a number of existing areas into even more areas since areas or from a number of existing areas into even more areas since
every OSPF interface with an area change is going down with its old every OSPF interface with an area change is going down with its old
area and then up with a new area. area and then up with a new area.
This document presents a topology-transparent zone (TTZ) in an OSPF This document presents a topology-transparent zone (TTZ) in an OSPF
area and describes extensions to OSPFv2 for supporting the topology- area and describes extensions to OSPFv2 for supporting the topology-
transparent zone, which is scalable and resolves the issues above. transparent zone, which is scalable and resolves the issues above. A
TTZ hides the internal topology of the TTZ from the outside. It does
not directly advertise any internal information about the TTZ to a
router outside of the TTZ.
2. Terminology 2. Terminology
TTZ link or TTZ internal link: A link whose ends are within a single TTZ link or TTZ internal link: A link whose ends are within a single
TTZ. TTZ.
TTZ internal router: A router whose links are TTZ internal links TTZ internal router: A router whose links are TTZ internal links
inside a single TTZ. inside a single TTZ.
TTZ external router: A router outside of a TTZ that has no TTZ TTZ external router: A router outside of a TTZ that has no TTZ
skipping to change at page 5, line 36 skipping to change at page 5, line 39
5. Topology-Transparent Zone 5. Topology-Transparent Zone
5.1. Overview of Topology-Transparent Zone 5.1. Overview of Topology-Transparent Zone
A Topology-Transparent Zone is identified by a TTZ identifier (ID), A Topology-Transparent Zone is identified by a TTZ identifier (ID),
and it consists of a group of routers and a number of links and it consists of a group of routers and a number of links
connecting the routers. A TTZ MUST be contained within an OSPF area. connecting the routers. A TTZ MUST be contained within an OSPF area.
A TTZ ID is a 32-bit number that is unique for identifying a TTZ. A TTZ ID is a 32-bit number that is unique for identifying a TTZ.
The TTZ ID SHOULD NOT be 0. The same TTZ ID MUST be configured on The TTZ ID SHOULD NOT be 0, to avoid confusion with Area 0. The same
the routers and/or links that make up a specific instance of a TTZ. TTZ ID MUST be configured on the routers and/or links that make up a
All TTZ instances in a network MUST be unique. specific instance of a TTZ. All TTZ instances in an OSPF area MUST
be unique.
In addition to having similar functions of an OSPF area, an OSPF TTZ In addition to having similar functions of an OSPF area, an OSPF TTZ
makes some improvements on an OSPF area, which include: makes some improvements on an OSPF area, which include:
o An OSPF TTZ represents a set of TTZ edge routers, connected by a o An OSPF TTZ represents a set of TTZ edge routers, connected by a
full mesh of virtual connections between them. full mesh of virtual connections between them.
o Non-TTZ link state information is handled as normal. TTZ Routers o Non-TTZ link state information is handled as normal. TTZ Routers
receive the link state information about the topology outside of receive the link state information about the topology outside of
the TTZ, store the information, and flood the information through the TTZ, store the information, and flood the information through
skipping to change at page 8, line 19 skipping to change at page 8, line 23
6.1. General Format of TTZ LSA 6.1. General Format of TTZ LSA
The following is the general format of a TTZ LSA. It has an LS Type The following is the general format of a TTZ LSA. It has an LS Type
= 10/9 and TTZ-LSA-Type, and contains a number of TLVs. = 10/9 and TTZ-LSA-Type, and contains a number of TLVs.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LS age | Options | LS Type = 10/9| | LS age | Options | LS Type = 10/9|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|TTZ-LSA-Type(TBD)| Instance ID | |TTZ-LSA-Type(9)| Instance ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Advertising Router | | Advertising Router |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LS Sequence Number | | LS Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LS checksum | Length | | LS checksum | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
~ TLVs ~ ~ TLVs ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 9, line 13 skipping to change at page 9, line 13
optional TTZ Options TLV. optional TTZ Options TLV.
6.2. TTZ ID TLV 6.2. TTZ ID TLV
A TTZ ID TLV has the following format. It contains a TTZ ID (refer A TTZ ID TLV has the following format. It contains a TTZ ID (refer
to section 5.1) and some flags. It has the TLV-Length of 8 octets. to section 5.1) and some flags. It has the TLV-Length of 8 octets.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TTZ-ID-TLV-Type (TBD) | TLV-Length (8) | | TTZ-ID-TLV-Type (1) | TLV-Length (8) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TTZ ID | | TTZ ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved (MUST be zero) |E|Z| | Reserved (MUST be zero) |E|Z|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
E = 1: Indicating a router is a TTZ Edge router E = 1: Indicating a router is a TTZ Edge router
Z = 1: Indicating a router has migrated to TTZ Z = 1: Indicating a router has migrated to TTZ
When a TTZ router originates a TTZ LSA containing a TTZ ID TLV, it When a TTZ router originates a TTZ LSA containing a TTZ ID TLV, it
sets flag E to 1 in the TTZ ID TLV if it is a TTZ edge router, and to MUST set flag E to 1 in the TTZ ID TLV if it is a TTZ edge router,
0 if it is a TTZ internal router. It sets flag Z to 1 after it has and to 0 if it is a TTZ internal router. It MUST set flag Z to 1
migrated to TTZ, and to 0 before it migrates to TTZ or after it rolls after it has migrated to TTZ, and to 0 before it migrates to TTZ or
back from TTZ (refer to section 6.4). after it rolls back from TTZ (refer to section 6.4).
6.3. TTZ Router TLV 6.3. TTZ Router TLV
The format of a TTZ Router TLV is as follows. It has the same The format of a TTZ Router TLV is as follows. It has the same
content as a standard OSPF Router LSA (RFC 2328) with the following content as a standard OSPF Router LSA (RFC 2328) with the following
modifications. modifications.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TTZ-RT-TLV-Type (TBD) | TLV-Length | | TTZ-RT-TLV-Type (2) | TLV-Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0 |V|E|B| 0 | # links | | 0 |V|E|B| 0 | # links |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link ID | | Link ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Data | | Link Data |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | # TOS | metric | | Type | # TOS | metric |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ ... ~ ~ ... ~
skipping to change at page 10, line 26 skipping to change at page 10, line 26
reserved (refer to RFC 4940), which allows the reuse of the bottom 7 reserved (refer to RFC 4940), which allows the reuse of the bottom 7
bits to indicate the type of a TTZ internal or external link. bits to indicate the type of a TTZ internal or external link.
6.4. TTZ Options TLV 6.4. TTZ Options TLV
The format of a TTZ Options TLV is as follows. The format of a TTZ Options TLV is as follows.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TTZ-OP-TLV-Type (TBD) | TLV-Length | | TTZ-OP-TLV-Type (3) | TLV-Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OP | Reserved (MUST be zero) | | OP | Reserved (MUST be zero) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
OP Value Meaning (Operation) OP Value Meaning (Operation)
0x001 (T): Advertising TTZ Topology Information for Migration 0x001 (T): Advertising TTZ Topology Information for Migration
0x010 (M): Migrating to TTZ 0x010 (M): Migrating to TTZ
0x011 (N): Advertising Normal Topology Information for Rollback 0x011 (N): Advertising Normal Topology Information for Rollback
0x100 (R): Rolling back from TTZ 0x100 (R): Rolling back from TTZ
A OP field of three bits is defined. It may have a value of 0x001 A OP field of three bits is defined. It may have a value of 0x001
skipping to change at page 12, line 10 skipping to change at page 12, line 10
6.5. Link Scope TTZ LSA 6.5. Link Scope TTZ LSA
A TTZ LSA of LS Type 9 has the following format. A TTZ LSA of LS Type 9 has the following format.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LS age | Options | LS Type = 9 | | LS age | Options | LS Type = 9 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|TTZ-LSA-Type(TBD)| Instance ID | |TTZ-LSA-Type(9)| Instance ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Advertising Router | | Advertising Router |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LS Sequence Number | | LS Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LS checksum | Length | | LS checksum | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
~ TTZ ID TLV ~ ~ TTZ ID TLV ~
+---------------------------------------------------------------+ +---------------------------------------------------------------+
skipping to change at page 12, line 34 skipping to change at page 12, line 34
It contains a mandatory TTZ ID TLV, which may be followed by a It contains a mandatory TTZ ID TLV, which may be followed by a
optional TTZ Options TLV. It is used to discover a TTZ neighbor. optional TTZ Options TLV. It is used to discover a TTZ neighbor.
7. Constructing LSAs for TTZ 7. Constructing LSAs for TTZ
For a TTZ, its topology is represented by the LSAs generated by its For a TTZ, its topology is represented by the LSAs generated by its
TTZ routers for the link states in the TTZ, which include TTZ router TTZ routers for the link states in the TTZ, which include TTZ router
LSAs by TTZ edge routers, TTZ indication LSAs by TTZ internal LSAs by TTZ edge routers, TTZ indication LSAs by TTZ internal
routers, normal router LSAs and network LSAs. The TTZ router LSAs routers, normal router LSAs and network LSAs. The TTZ router LSAs
and TTZ indication LSAs are generated after advertising TTZ topology and TTZ indication LSAs MUST be generated after advertising TTZ
information for migration is triggered. topology information for migration is triggered.
A TTZ edge router generates a TTZ router LSA that has a TTZ ID TLV A TTZ edge router generates a TTZ router LSA that has a TTZ ID TLV
and a TTZ Router TLV. The former includes the ID of the TTZ to which and a TTZ Router TLV. The former includes the ID of the TTZ to which
the router belongs and flag E set to 1, which indicates the the router belongs and flag E set to 1, which indicates the
originator of the LSA is a TTZ Edge router. The TTZ router TLV originator of the LSA is a TTZ Edge router. The TTZ router TLV
contains the TTZ external links to the routers outside of the TTZ and contains the TTZ external links to the routers outside of the TTZ and
the TTZ internal links to the routers inside the TTZ as described in the TTZ internal links to the routers inside the TTZ as described in
section 6. The TTZ router LSA containing this TLV is constructed and section 6. The TTZ router LSA containing this TLV is constructed and
advertised within the TTZ. advertised within the TTZ.
A TTZ internal router generates a TTZ indication LSA that has a TTZ A TTZ internal router generates a TTZ indication LSA that has a TTZ
ID TLV containing the ID of the TTZ to which the router belongs and ID TLV containing the ID of the TTZ to which the router belongs and
flag E set to 0, which indicates the originator of the LSA is a TTZ flag E set to 0, which indicates the originator of the LSA is a TTZ
internal router. For a TTZ internal router, its regular Router LSA internal router. For a TTZ internal router, its regular Router LSA
is still generated. If a TTZ router is a DR, it originates its is still generated. If a TTZ router is a Designated Router (DR), it
regular network LSA. originates its regular network LSA.
After receiving a trigger to migrate to TTZ such as a TTZ control LSA After receiving a trigger to migrate to TTZ such as a TTZ control LSA
with OP for M, a TTZ edge router originates its normal router LSA for with OP for M, a TTZ edge router MUST originate its normal router LSA
virtualizing a TTZ, which comprises three groups of links in general. for virtualizing a TTZ, which comprises three groups of links in
general.
The first group are the router links connecting the TTZ external The first group are the router links connecting the TTZ external
routers. These router links are normal router links. There is a routers. These router links are normal router links. There is a
router link for every adjacency between this TTZ edge router and a router link for every adjacency between this TTZ edge router and a
TTZ external router. TTZ external router.
The second group are the "virtual" router links connecting to the The second group are the "virtual" router links connecting to the
other TTZ edge routers. For each of the other TTZ edge routers, other TTZ edge routers. For each of the other TTZ edge routers,
there is a corresponding point-to-point router link to it from this there is a corresponding point-to-point router link to it from this
TTZ edge router. The cost of the link is the cost of the shortest TTZ edge router. The cost of the link is the cost of the shortest
skipping to change at page 14, line 21 skipping to change at page 14, line 22
a route taking a path through the TTZ in the TTZ external router may a route taking a path through the TTZ in the TTZ external router may
be down or changed before all the router LSAs generated by the TTZ be down or changed before all the router LSAs generated by the TTZ
edge routers reach the TTZ external router. When the TTZ external edge routers reach the TTZ external router. When the TTZ external
router computes routes with some router LSAs originated by the TTZ router computes routes with some router LSAs originated by the TTZ
edge routers, bi-directional check for some of the point-to-point edge routers, bi-directional check for some of the point-to-point
links will fail. Thus the route taking the path through the shortest links will fail. Thus the route taking the path through the shortest
path for the point-to-point link failing the bi-directional check path for the point-to-point link failing the bi-directional check
will be down or changed. will be down or changed.
To roll back from a TTZ smoothly after receiving a trigger to roll To roll back from a TTZ smoothly after receiving a trigger to roll
back from TTZ, a TTZ edge router originates its normal router LSA in back from TTZ, a TTZ edge router MUST originate its normal router LSA
the above two steps in a reverse way. in the above two steps in a reverse way.
Step 1: Initially, it updates its normal router LSA by adding the Step 1: Initially, it updates its normal router LSA by adding the
normal links for the links configured as TTZ links into the LSA. normal links for the links configured as TTZ links into the LSA.
Step 2: It then removes the point-to-point links to the other edge Step 2: It then removes the point-to-point links to the other edge
routers of the TTZ for virtualizing the TTZ and the stub links for routers of the TTZ for virtualizing the TTZ and the stub links for
the loopback addresses from its updated router LSA after sending the loopback addresses from its updated router LSA after sending
its updated router LSA and receiving the updated router LSAs its updated router LSA and receiving the updated router LSAs
originated by the other TTZ edge routers for MaxLSAAdvTime or originated by the other TTZ edge routers for MaxLSAAdvTime or
after sending its updated router LSA for MaxLSAGenAdvTime. after sending its updated router LSA for MaxLSAGenAdvTime.
skipping to change at page 16, line 30 skipping to change at page 16, line 32
When B receives the D-LSA from A with OP for M, it starts to migrate When B receives the D-LSA from A with OP for M, it starts to migrate
to TTZ. B updates and advertises its LSAs as needed. to TTZ. B updates and advertises its LSAs as needed.
After receiving B's D-LSA with Z = 1, A updates and sends B its D-LSA After receiving B's D-LSA with Z = 1, A updates and sends B its D-LSA
by removing the TTZ Options TLV. It also updates and advertises its by removing the TTZ Options TLV. It also updates and advertises its
LSAs as needed. LSAs as needed.
For a number of routers connected through a broadcast link and having For a number of routers connected through a broadcast link and having
normal adjacencies among them, they also TTZ discover each other normal adjacencies among them, they also TTZ discover each other
through D-LSAs. The DR for the link MUST "form" TTZ adjacencies with through D-LSAs. The DR (Designated Router) for the link MUST "form"
the other routers if all the routers attached to the link have the TTZ adjacencies with the other routers if all the routers attached to
same TTZ ID configured on the connections to the link. Otherwise, the link have the same TTZ ID configured on the connections to the
the DR MUST NOT "form" any TTZ adjacency with any router attached to link. Otherwise, the DR MUST NOT "form" any TTZ adjacency with any
the link. router attached to the link.
For a number of routers connected through a broadcast link and having For a number of routers connected through a broadcast link and having
TTZ adjacencies among them, if a mis-configured router is introduced TTZ adjacencies among them, if a mis-configured router is introduced
on the broadcast link, the DR for the link MUST NOT "form" any TTZ on the broadcast link, the DR for the link MUST NOT "form" any TTZ
adjacency with this mis-configured router. adjacency with this mis-configured router.
For routers connected via a link without any adjacency among them, For routers connected via a link without any adjacency among them,
they TTZ discover each other through D-LSAs in the same way as they TTZ discover each other through D-LSAs in the same way as
described above after they form a normal adjacency. described above after they form a normal adjacency.
skipping to change at page 22, line 26 skipping to change at page 22, line 28
TTZ on a router and/or an interface on a router. The TTZ function TTZ on a router and/or an interface on a router. The TTZ function
may be controlled by a policy module and assigned a suitable user may be controlled by a policy module and assigned a suitable user
privilege level to enable. A suitable model may be required to privilege level to enable. A suitable model may be required to
verify the TTZ status on routers participating in the TTZ, including verify the TTZ status on routers participating in the TTZ, including
their role as internal or edge TTZ router. The mechanisms defined in their role as internal or edge TTZ router. The mechanisms defined in
this document do not imply any new liveness detection and monitoring this document do not imply any new liveness detection and monitoring
requirements in addition to those indicated in [RFC2328]. requirements in addition to those indicated in [RFC2328].
13. Security Considerations 13. Security Considerations
The mechanism described in this document does not raise any new A notable beneficial security aspect of TTZ is that the TTZ is
security issues for OSPF since a TTZ is enclosed in a single area. enclosed in a single area, and TTZ could be used to mask the internal
Of special concern in a TTZ is the ability of a malicious node to topology. External routers that are not participating in the TTZ
inject TTZ LSAs with the OP field set to M or R, which could trigger will not be aware of the internal TTZ topology. It should be noted
the migration into/from a TTZ and may result in the isolation of some that a malicious node could inject TTZ LSAs with the OP Field set to
routers in the network. A TTZ relies on authentication and other M or R, which could trigger the migration into/from a TTZ and may
existing OSPF security mechanisms [RFC2328] [RFC7474] to mitigate result in the isolation of some routers in the network. Good
security practice might reuse the OSPF authentication and other
security mechanisms described in [RFC2328] and [RFC7474], to mitigate
this type of risk. this type of risk.
14. IANA Considerations 14. IANA Considerations
Under Registry Name: Opaque Link-State Advertisements (LSA) Option Under Registry Name: Opaque Link-State Advertisements (LSA) Option
Types [RFC5250], IANA is requested to assign a new Opaque type Types [RFC5250], IANA is requested to assign a new Opaque type
registry value for Topology-Transparent Zone (TTZ) LSA as follows: registry value for Topology-Transparent Zone (TTZ) LSA as follows:
+====================+===============+=======================+ +====================+===============+=======================+
| Registry Value | Opaque Type | reference | | Registry Value | Opaque Type | reference |
+====================+===============+=======================+ +====================+===============+=======================+
| IANA TBD | TTZ LSA | This document | | IANA TBD | TTZ LSA | This document |
| (9 Suggested) | | | | (9 Suggested) | | |
+--------------------+---------------+-----------------------+ +--------------------+---------------+-----------------------+
IANA is requested to assign Types for new TLVs in the new TTZ LSA as IANA is to create and maintain a new registry:
follows:
Type Name Allowed in o OSPFv2 TTZ LSA TLVs
1 TTZ ID TLV TTZ LSA of LS Type 10 and 9
2 TTZ Router TLV TTZ LSA of LS Type 10 Initial values for the registry are given below. The future
3 TTZ Options TLV TTZ LSA of LS Type 10 and 9 assignments are to be made through IETF Review.
Value OSPFv2 TTZ LSA TLV Name Definition
----- ----------------------- ----------
0 Reserved
1 TTZ ID TLV see section 6.2
2 TTZ Router TLV see section 6.3
3 TTZ Options TLV see section 6.4
4-32767 Unassigned
32768-65535 Reserved
15. Contributors and Other Authors 15. Contributors and Other Authors
1. Other Authors 1. Other Authors
Mehmet Toy
USA
Email: mehmet.toy@verizon.com
Gregory Cauchie Gregory Cauchie
FRANCE FRANCE
Email: greg.cauchie@gmail.com Email: greg.cauchie@gmail.com
Anil Kumar S N Anil Kumar S N
India India
Email: anil.sn@huawei.com Email: anil.sn@huawei.com
Ning So Ning So
USA USA
skipping to change at page 27, line 21 skipping to change at page 27, line 37
Alvaro Retana Alvaro Retana
Cisco Systems, Inc. Cisco Systems, Inc.
7025 Kit Creek Rd. 7025 Kit Creek Rd.
Raleigh, NC 27709 Raleigh, NC 27709
USA USA
Email: aretana@cisco.com Email: aretana@cisco.com
Yi Yang Yi Yang
Sockrate
USA USA
Email: yyang1998@gmail.com Email: yyang1998@gmail.com
Zhiheng Liu
Vic Liu
China Mobile China Mobile
No.32 Xuanwumen West Street, Xicheng District No.32 Xuanwumen West Street, Xicheng District
Beijing, 100053 Beijing, 100053
China China
Email: liu.cmri@gmail.com Email: liu.cmri@gmail.com
Mehmet Toy
Verizon
USA
Email: mtoy054@yahoo.com
 End of changes. 30 change blocks. 
59 lines changed or deleted 78 lines changed or added

This html diff was produced by rfcdiff 1.45. The latest version is available from http://tools.ietf.org/tools/rfcdiff/