draft-ietf-ospf-segment-routing-extensions-26.txt   draft-ietf-ospf-segment-routing-extensions-27.txt 
Open Shortest Path First IGP P. Psenak, Ed. Open Shortest Path First IGP P. Psenak, Ed.
Internet-Draft S. Previdi, Ed. Internet-Draft S. Previdi, Ed.
Intended status: Standards Track C. Filsfils Intended status: Standards Track C. Filsfils
Expires: May 24, 2019 Cisco Systems, Inc. Expires: June 6, 2019 Cisco Systems, Inc.
H. Gredler H. Gredler
RtBrick Inc. RtBrick Inc.
R. Shakir R. Shakir
Google, Inc. Google, Inc.
W. Henderickx W. Henderickx
Nokia Nokia
J. Tantsura J. Tantsura
Apstra, Inc. Apstra, Inc.
November 20, 2018 December 3, 2018
OSPF Extensions for Segment Routing OSPF Extensions for Segment Routing
draft-ietf-ospf-segment-routing-extensions-26 draft-ietf-ospf-segment-routing-extensions-27
Abstract Abstract
Segment Routing (SR) allows a flexible definition of end-to-end paths Segment Routing (SR) allows a flexible definition of end-to-end paths
within IGP topologies by encoding paths as sequences of topological within IGP topologies by encoding paths as sequences of topological
sub-paths, called "segments". These segments are advertised by the sub-paths, called "segments". These segments are advertised by the
link-state routing protocols (IS-IS and OSPF). link-state routing protocols (IS-IS and OSPF).
This draft describes the OSPFv2 extensions required for Segment This draft describes the OSPFv2 extensions required for Segment
Routing. Routing.
skipping to change at page 2, line 4 skipping to change at page 2, line 4
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 https://datatracker.ietf.org/drafts/current/. Drafts is at https://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 May 24, 2019. This Internet-Draft will expire on June 6, 2019.
Copyright Notice Copyright Notice
Copyright (c) 2018 IETF Trust and the persons identified as the Copyright (c) 2018 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
(https://trustee.ietf.org/license-info) in effect on the date of (https://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
skipping to change at page 2, line 34 skipping to change at page 2, line 34
2. Segment Routing Identifiers . . . . . . . . . . . . . . . . . 3 2. Segment Routing Identifiers . . . . . . . . . . . . . . . . . 3
2.1. SID/Label Sub-TLV . . . . . . . . . . . . . . . . . . . . 4 2.1. SID/Label Sub-TLV . . . . . . . . . . . . . . . . . . . . 4
3. Segment Routing Capabilities . . . . . . . . . . . . . . . . 4 3. Segment Routing Capabilities . . . . . . . . . . . . . . . . 4
3.1. SR-Algorithm TLV . . . . . . . . . . . . . . . . . . . . 4 3.1. SR-Algorithm TLV . . . . . . . . . . . . . . . . . . . . 4
3.2. SID/Label Range TLV . . . . . . . . . . . . . . . . . . . 6 3.2. SID/Label Range TLV . . . . . . . . . . . . . . . . . . . 6
3.3. SR Local Block TLV . . . . . . . . . . . . . . . . . . . 8 3.3. SR Local Block TLV . . . . . . . . . . . . . . . . . . . 8
3.4. SRMS Preference TLV . . . . . . . . . . . . . . . . . . . 10 3.4. SRMS Preference TLV . . . . . . . . . . . . . . . . . . . 10
4. OSPF Extended Prefix Range TLV . . . . . . . . . . . . . . . 11 4. OSPF Extended Prefix Range TLV . . . . . . . . . . . . . . . 11
5. Prefix SID Sub-TLV . . . . . . . . . . . . . . . . . . . . . 13 5. Prefix SID Sub-TLV . . . . . . . . . . . . . . . . . . . . . 13
6. Adjacency Segment Identifier (Adj-SID) . . . . . . . . . . . 16 6. Adjacency Segment Identifier (Adj-SID) . . . . . . . . . . . 16
6.1. Adj-SID Sub-TLV . . . . . . . . . . . . . . . . . . . . . 16 6.1. Adj-SID Sub-TLV . . . . . . . . . . . . . . . . . . . . . 17
6.2. LAN Adj-SID Sub-TLV . . . . . . . . . . . . . . . . . . . 18 6.2. LAN Adj-SID Sub-TLV . . . . . . . . . . . . . . . . . . . 18
7. Elements of Procedure . . . . . . . . . . . . . . . . . . . . 19 7. Elements of Procedure . . . . . . . . . . . . . . . . . . . . 19
7.1. Intra-area Segment routing in OSPFv2 . . . . . . . . . . 20 7.1. Intra-area Segment routing in OSPFv2 . . . . . . . . . . 19
7.2. Inter-area Segment routing in OSPFv2 . . . . . . . . . . 20 7.2. Inter-area Segment routing in OSPFv2 . . . . . . . . . . 20
7.3. Segment Routing for External Prefixes . . . . . . . . . . 21 7.3. Segment Routing for External Prefixes . . . . . . . . . . 21
7.4. Advertisement of Adj-SID . . . . . . . . . . . . . . . . 22 7.4. Advertisement of Adj-SID . . . . . . . . . . . . . . . . 22
7.4.1. Advertisement of Adj-SID on Point-to-Point Links . . 22 7.4.1. Advertisement of Adj-SID on Point-to-Point Links . . 22
7.4.2. Adjacency SID on Broadcast or NBMA Interfaces . . . . 22 7.4.2. Adjacency SID on Broadcast or NBMA Interfaces . . . . 22
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22
8.1. OSPF Router Information (RI) TLVs Registry . . . . . . . 23 8.1. OSPF Router Information (RI) TLVs Registry . . . . . . . 22
8.2. OSPFv2 Extended Prefix Opaque LSA TLVs Registry . . . . . 23 8.2. OSPFv2 Extended Prefix Opaque LSA TLVs Registry . . . . . 23
8.3. OSPFv2 Extended Prefix TLV Sub-TLVs Registry . . . . . . 23 8.3. OSPFv2 Extended Prefix TLV Sub-TLVs Registry . . . . . . 23
8.4. OSPFv2 Extended Link TLV Sub-TLVs Registry . . . . . . . 23 8.4. OSPFv2 Extended Link TLV Sub-TLVs Registry . . . . . . . 23
8.5. IGP Algorithm Type Registry . . . . . . . . . . . . . . . 23 8.5. IGP Algorithm Type Registry . . . . . . . . . . . . . . . 23
9. Implementation Status . . . . . . . . . . . . . . . . . . . . 24 9. Implementation Status . . . . . . . . . . . . . . . . . . . . 24
10. Security Considerations . . . . . . . . . . . . . . . . . . . 25 10. Security Considerations . . . . . . . . . . . . . . . . . . . 25
11. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 26 11. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 26
12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 26 12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 26
13. References . . . . . . . . . . . . . . . . . . . . . . . . . 26 13. References . . . . . . . . . . . . . . . . . . . . . . . . . 26
13.1. Normative References . . . . . . . . . . . . . . . . . . 26 13.1. Normative References . . . . . . . . . . . . . . . . . . 26
skipping to change at page 14, line 34 skipping to change at page 14, line 34
MT-ID: Multi-Topology ID (as defined in [RFC4915]). MT-ID: Multi-Topology ID (as defined in [RFC4915]).
Algorithm: Single octet identifying the algorithm the Prefix-SID Algorithm: Single octet identifying the algorithm the Prefix-SID
is associated with as defined in Section 3.1. is associated with as defined in Section 3.1.
A router receiving a Prefix-SID from a remote node and with an A router receiving a Prefix-SID from a remote node and with an
algorithm value that such remote node has not advertised in the algorithm value that such remote node has not advertised in the
SR-Algorithm Sub-TLV (Section 3.1) MUST ignore the Prefix-SID Sub- SR-Algorithm Sub-TLV (Section 3.1) MUST ignore the Prefix-SID Sub-
TLV. TLV.
SID/Index/Label: According to the V and L flags, it contains SID/Index/Label: According to the V and L flags, it contains:
either:
A 32-bit index defining the offset in the SID/Label space V-flag is set to 0 and L-flag is set to 0: The SID/Index/Label
advertised by this router. field is a 4 octet index defining the offset in the SID/Label
space advertised by this router
A 24-bit label where the 20 rightmost bits are used for V-flag is set to 1 and L-flag is set to 1: The SID/Index/Label
encoding the label value. field is a 3 octet local label where the 20 rightmost bits are
used for encoding the label value.
All other combinations of V-flag and L-flag are invalid and any
SID advertisement received with an invalid setting for V and L
flags MUST be ignored.
If an OSPF router advertises multiple Prefix-SIDs for the same If an OSPF router advertises multiple Prefix-SIDs for the same
prefix, topology and algorithm, all of them MUST be ignored. prefix, topology and algorithm, all of them MUST be ignored.
When calculating the outgoing label for the prefix, the router MUST When calculating the outgoing label for the prefix, the router MUST
take into account, as described below, the E, NP and M flags take into account, as described below, the E, NP and M flags
advertised by the next-hop router if that router advertised the SID advertised by the next-hop router if that router advertised the SID
for the prefix. This MUST be done regardless of whether the next-hop for the prefix. This MUST be done regardless of whether the next-hop
router contributes to the best path to the prefix. router contributes to the best path to the prefix.
skipping to change at page 18, line 16 skipping to change at page 18, line 20
ignored when received. ignored when received.
Reserved: SHOULD be set to 0 on transmission and MUST be ignored Reserved: SHOULD be set to 0 on transmission and MUST be ignored
on reception. on reception.
MT-ID: Multi-Topology ID (as defined in [RFC4915]. MT-ID: Multi-Topology ID (as defined in [RFC4915].
Weight: Weight used for load-balancing purposes. The use of the Weight: Weight used for load-balancing purposes. The use of the
weight is defined in [I-D.ietf-spring-segment-routing]. weight is defined in [I-D.ietf-spring-segment-routing].
SID/Index/Label: According to the V and L flags, it contains SID/Index/Label: as described in Section 5.
either:
A 32-bit index defining the offset in the SID/Label space
advertised by this router.
A 24-bit label where the 20 rightmost bits are used for
encoding the label value.
An SR capable router MAY allocate an Adj-SID for each of its An SR capable router MAY allocate an Adj-SID for each of its
adjacencies and set the B-Flag when the adjacency is eligible for adjacencies and set the B-Flag when the adjacency is eligible for
protection by an FRR mechanism (IP or MPLS) as described in section protection by an FRR mechanism (IP or MPLS) as described in section
3.5 of [I-D.ietf-spring-segment-routing]. 3.5 of [I-D.ietf-spring-segment-routing].
An SR capable router MAY allocate more than one Adj-SID to an An SR capable router MAY allocate more than one Adj-SID to an
adjacency adjacency
An SR capable router MAY allocate the same Adj-SID to different An SR capable router MAY allocate the same Adj-SID to different
skipping to change at page 19, line 36 skipping to change at page 19, line 36
on reception. on reception.
MT-ID: Multi-Topology ID (as defined in [RFC4915]. MT-ID: Multi-Topology ID (as defined in [RFC4915].
Weight: Weight used for load-balancing purposes. The use of the Weight: Weight used for load-balancing purposes. The use of the
weight is defined in [I-D.ietf-spring-segment-routing]. weight is defined in [I-D.ietf-spring-segment-routing].
Neighbor ID: The Router ID of the neighbor for which the LAN-Adj- Neighbor ID: The Router ID of the neighbor for which the LAN-Adj-
SID is advertised. SID is advertised.
SID/Index/Label: According to the V and L flags, it contains SID/Index/Label: as described in Section 5.
either:
A 32-bit index defining the offset in the SID/Label space
advertised by this router.
A 24-bit label where the 20 rightmost bits are used for
encoding the label value.
When the P-flag is not set, the Adj-SID MAY be persistent. When When the P-flag is not set, the Adj-SID MAY be persistent. When
the P-flag is set, the Adj-SID MUST be persistent. the P-flag is set, the Adj-SID MUST be persistent.
7. Elements of Procedure 7. Elements of Procedure
7.1. Intra-area Segment routing in OSPFv2 7.1. Intra-area Segment routing in OSPFv2
An OSPFv2 router that supports segment routing MAY advertise Prefix- An OSPFv2 router that supports segment routing MAY advertise Prefix-
SIDs for any prefix to which it is advertising reachability (e.g., a SIDs for any prefix to which it is advertising reachability (e.g., a
loopback IP address as described in Section 5). loopback IP address as described in Section 5).
A Prefix-SID can also be advertised by the SR Mapping Servers (as A Prefix-SID can also be advertised by the SR Mapping Servers (as
described in [I-D.ietf-spring-segment-routing-ldp-interop]). A described in [I-D.ietf-spring-segment-routing-ldp-interop]). A
Mapping Server advertises Prefix-SIDs for remote prefixes that exist Mapping Server advertises Prefix-SIDs for remote prefixes that exist
in the OSPFv2 routing domain. Multiple Mapping Servers can advertise in the OSPFv2 routing domain. Multiple Mapping Servers can advertise
 End of changes. 13 change blocks. 
29 lines changed or deleted 21 lines changed or added

This html diff was produced by rfcdiff 1.47. The latest version is available from http://tools.ietf.org/tools/rfcdiff/