1. ISIS extensions for SRv6 draft-bashandy-isis-srv6-extensions-02
Ahmed Bashandy, Cisco Systems
Clarence Filsfils, Cisco Systems
Les Ginsberg, Cisco Systems
Bruno Decraene, Orange
Zhibo Hu, Huawei
101st IETF, London, March 2018

2. Key SRv6 Documents draft-filsfils-spring-srv6-network-programming
draft-ietf-6man-segment-routing-header
101st IETF, London, March 2018

3. draft-li-ospf-ospfv3-srv6-extensions-01
OSPFv3 Equivalent
draft-li-ospf-ospfv3-srv6-extensions-01
Zhenbin Li, Huawei Technologies
Zhibo Hu, Huawei Technologies
Dean Cheng, Huawei Technologies
Ketan Talaulikar, Cisco Systems
Peter Psenak, Cisco Systems
101st IETF, London, March 2018

4. Changes since V1
Alignment with latest Network Programming Draft/function registry and terminology
Support for OAM (O-bit in SRH and End.OTP function) added
Convert Function Descriptor from sub-TLV to direct encoding in the appropriate TLV/sub-TLVs (multiple functions/SID is not required)
Some TLV/sub-TLVs renamed for clarity
101st IETF, London, March 2018

5. New Advertisements SRv6 Capabilities (sub-TLV of Router Capabilities)
SRv6 Node SIDs (new top level TLV)
Endpoint functions types associated w SRv6 Node SIDs
SRv6 SIDs Associated w a Neighbor (sub-TLVs of IS-Neighbor)
101st IETF, London, March 2018

6. SRv6 Capabilities Sub-TLV
| Type | Length | Flags |
| Optional sub-sub-TLVs … |
Flags
|E|O| Reserved |
E-flag: Indicates router is able to apply "T.Encap“ function
O-flag: Indicates the router supports use of the O-bit in SRH (OAM)
sub-sub-TLVs:
| Type | Length | Value |
Used to advertise the support for SRv6 and the limitation on such support
101st IETF, London, March 2018

7. SRv6 Capabilities Sub-sub-TLVs
Max-SL: Maximum Received SL in the SRH
Max-End-Pop-SRH: Maximum number of SIDs when applying PSP or USP flavors (0 => not supported)
Max-T-Ins-SRH: Maximum number of SIDs when applying T.insert (0 => not supported)
Max-T-Encap-SRH: Maximum number of SIDs when applying T.Encap (Valid when E-flag is set)
Max-End-D-SRH: Maximum number of SIDs when applying End.DX6 or End.DT6
Used to advertise the support for SRv6 and the limitation on such support
101st IETF, London, March 2018

8. SRv6 Endpoint Function Descriptor
| Func-flags |
| Endpoint Function |
No func-flags defined Endpoint Functions:
End (no PSP, no USP)
End.X with USP
End with PSP
End.X with PSP&USP
End with USP
End.DX6 Function
End with PSP&USP
End.DT6 Function
End.X (no PSP, no USP)
End.OTP
End.X with PSP
* E.g.
Different leaking/propagating policy
Different tagging (e.g admit tags)
** For End and End.DT, not for End.X and End.DX
101st IETF, London, March 2018

9. SRv6 Node SID TLV Top Level TLV
Non-SRv6 capable nodes ignore this TLV
Not a prefix to be installed in RIB/FIB
Minimum impact on existing routing functionality
Advertises SRv6 Node SIDs and the associated attributes
Used for SIDs not related to neighbors
Does NOT result in routing action on its own
Shares sub-TLV space with prefix reachability TLV (135/235/236/237)
Can be leaked between levels
Advertised SRv6 SID need not be covered by IPv6 prefix reachability (TLV 236 and 237)
E.g. may be reachable via static route
* E.g.
Different leaking/propagating policy
Different tagging (e.g admit tags)
** For End and End.DT, not for End.X and End.DX
101st IETF, London, March 2018

10. SRv6 Node SID
| Type | Length |
| Flags | Func-flags | Endpoint function Value |
| SID size | SID (variable) . . .
| sub-tlv-len | Sub-TLVs (variable) |
Flags: |D| Reserved | D bit: When the SID is leaked from level-2 to level-1, the D bit MUST be set. Function variants: End, End.OTP
* E.g.
Different leaking/propagating policy
Different tagging (e.g admit tags)
** For End and End.DT, not for End.X and End.DX
101st IETF, London, March 2018

11. SRv6 Node SID (cont) SID size: 1-128 (typically 128)
| Type | Length |
| Flags | Func-flags | Endpoint function Value |
| SID size | SID (variable) . . .
| sub-tlv-len | Sub-TLVs (variable) |
SID size: (typically 128)
SID: (SID size +7)/8 octets
Sub-TLVs: None defined yet
* E.g.
Different leaking/propagating policy
Different tagging (e.g admit tags)
** For End and End.DT, not for End.X and End.DX
101st IETF, London, March 2018

12. SRv6 Adjacency sub-TLV
| Type | Length |
| Flags | Func-flags | Endpoint function Value |
| SID size | SID (variable) . . .
| sub-tlv-len | Sub-TLVs (variable) |
Sub-TLV of neighbor reachability for P2P adjacency
Same structure as SRv6 Node SID TLV
No flags defined
Function variants:
End.X, End.DX
101st IETF, London, March 2018

13. SRv6 LAN Adjacency sub-TLV
| Type | Length | System ID (6 octets) | |
| |
| Flags | Func-flags | Endpoint function Value |
| SID size | SID (variable) . . .
| sub-tlv-len | Sub-TLVs (variable) |
Sub-TLV of neighbor reachability for LAN adjacency
Same structure as SRv6 Adjacency SID TLV plus neighbor system-id
No flags defined
Function variants:
End.X, End.DX
101st IETF, London, March 2018

14. Next Step
WG adoption
101st IETF, London, March 2018