Devil's Advocate - Segment Routing, Why?

Mark Tinka mark.tinka at
Wed Jun 17 22:19:40 UTC 2020

On 17/Jun/20 20:40, Dave Bell wrote:

> I don't understand the point of SRv6. What equipment can support IPv6
> routing, but can't support MPLS label switching?


Anything that can support LDPv4 today can support LDPv6, in hardware.

SRv6 and SRv6+ is a whole other issue, not to mention the amount of work
needed to write code for it.

> Not just this, but the LFA path is always the post-convergence path.
> You don't get microloops.
> You can implement TE on top if that is your thing. No need to run
> RSVP. Another protocol you don't need to run.
> You don't need to throw out all your old kit, and replace with new in
> one go. You can incrementally roll it out, and leave islands of LDP
> where needed. LDP-SR interworking is pretty simple.
> We are currently introducing it into our core. It will probably be a
> while before we fully phase out LDP, but its definitely on the roadmap.

Happy to hear, and I have nothing against your choice if you are happy
with it.

But for a network that may not see the need in spending cycles doing
yet-another roll out, it tastes funny when you are forced down a new path.

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