SRv6 Capable NOS and Devices

Vincent Bernat bernat at
Tue Jan 11 15:52:05 UTC 2022

 ❦ 11 January 2022 09:16 -06, Colton Conor:

> I know the SRv6 is a fairly new technology. I am wondering which
> vendors and network operating systems fully support SRv6 today? Has
> anyone deployed this new technology?

Cisco on NCS devices have full support of SRv6 F1 (End, End.X, End.T,
End.DX4, End.DT4, End.DX6, End.DT6, End.DX2, with PSP/USD or USP,
H.Encaps.*), without any EVPN (so not End.DT2U AFAIK), from 7.2,
depending on hardware (Jericho 2-based platforms need 7.5). There may be
hardware restriction on the smaller NCS (NCS540). However, Cisco is
switching to SRv6 F3216, aka microsegments. The same behaviours are
supported. Beware there is a gap between being on the datasheet and not
running into various bugs. Staying close to what Cisco promotes will
help avoiding some bugs. With ISIS as an IGP, there is also support for
TI-LFA and FlexAlgo.

Juniper supports SRv6 F1 on MX, with the same feature set. Nokia
supports it too on the 7750 SR. No support from Arista yet.

Iliad deployed SRv6 in Italy (and partly in France), with Cisco.

> If building a greenfield regional ISP network, would SRv6 be a
> requirement?

Dunno. This is still super young and you restrict the number of vendors
you can select and interoperate with. Also note that SRv6 F3216 RFC is
not out yet and Cisco is already asking customers to move away from SRv6
F1. AFAIK, other vendors are still on F1. Starting with SRv6 now may be
a bit of a gamble because of that. Latest draft is here:

> My understanding is that because it's using IPv6 in the dataplane, not
> all devices have to have SRv6 enabled. The in-between core devices
> just have to support IPv6, but not necessarily support SRv6. This is
> much different than traditional MPLS networks today where all devices
> have to support MPLS/LDP correct?

That's correct.
Use library functions.
            - The Elements of Programming Style (Kernighan & Plauger)

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