Segment routing version 6

[Karlos]

Hi folks!

I have subscribed the Cisco cml and I am only wondering which Cisco ios of cml can support running SRv6 ?

I will be thankful to all your answers.

[a-gould]

Hi Karlos, IOS-XR 7.2.2 - it's the version that came with my refplat file when I installed CML.  7.2.2 is what is seen on the IOS XR 9000v node.  I have created an instructional video to show SRv6 in CML  Hope it helps.

SRv6 in CML using XRv9k IOS-XR 7.2.2
https://youtu.be/SrryHbjpnAc 

other CML intro videos...
https://www.youtube.com/watch?v=1td1FDL0-Iw 
https://www.youtube.com/watch?v=C7gA2a64yBI 

[Karlos]

Thank you for your reply. I will watch your video. but just a question the cml you are using is personal right ?

[a-gould · Accepted solution]

Yes personal 20 node, which I mention in the intro video also

[Karlos]

Thank you for the reply and for your videos. last question if you do not mind, does Cisco 9000 xrv 7.2.2 that is mentioned in your video support SRv6 with OSPF or only with ISIS ? thank you again.

[a-gould]

You're welcome Karlos... short answer... no.  I haven't been able to find any evidence that OSPF(v3) supports SR (SRv6)...I'm only able to use IS-IS as the IGP for SRv6. 

longer answer...

I think this may speak to the IP-agnostic beginnings of IS-IS as an ISO protocol from years ago... and that IS-IS views IPv4 and IPv6 no different than the other. But, conversely, OSPF has an IPv4 origin with OSPFv2 (IPv4) and then had to be modified to support IPv6 in OSPFv3.

Also, when comparing the two Link State IGP's, OSPF and IS-IS, I understand IS-IS often has earlier support for new SP/Carrier-grade technologies... like SRv6

BTW, I have configured SR-MPLS in XRv9K using OSPFv2 as the core IGP (XR 6.3.1), but I don't think you are asking about SR-MPLS... rather, you are asking specifically about SRv6....

So, regarding SRv6, I have previously only been able to configure SRv6 over IS-IS as the IGP, and I did it in EVE-NG using XRv9K using IOS-XR 7.0.2 and now in CML using XRv9K using IOS-XR 7.2.2

Interestingly, I'm seeing OSPFv3 in Nexus 9000 supports SRv6... but I can't find this in my IOS-XR 7.2.2 node in my CML topology.
https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus9000/sw/93x/srv6/Configuration/guide/cisco-nexus-9000-series-nx-os-srv6-configuration-guide-93x/b-cisco-nexus-9000-series-nx-os-srv6-configuration-guide-93x_chapter_002.html#Cisco_Task.di... 

I don't know for sure if IOS-XR supports SRv6 in OSPFv3 yet....but I'm not finding any evidence that it does.

I wonder if Cisco just hasn't built SRv6 into OSPFv3 yet. Here are some of the standards that mention it.

OSPFv3 Segment Routing
https://datatracker.ietf.org/doc/html/draft-ietf-ospf-ospfv3-segment-routing-extensions-23 
https://datatracker.ietf.org/doc/html/rfc8666 
https://datatracker.ietf.org/doc/html/draft-li-ospf-ospfv3-srv6-extensions-01 
https://datatracker.ietf.org/doc/html/draft-ietf-ospf-ospfv3-segment-routing-extensions-01 

RFC 8402 mentions Link States needing to be extended to allow for SR... mentions OSPFv3 I think for SRv6...
https://datatracker.ietf.org/doc/html/rfc8402