Devil's Advocate - Segment Routing, Why?

adamv0025 at adamv0025 at
Thu Jun 18 12:30:29 UTC 2020

> From: Mark Tinka <mark.tinka at>
> Sent: Thursday, June 18, 2020 12:51 PM
> On 18/Jun/20 13:23, adamv0025 at wrote:
> >  is the current state is not the end state, this is a pretty dynamic industry
> that I'm sure is converging/evolving towards a v4:v6 parity, however the pace
> may be, which is understandable considering the scope of ground to be
> covered.
> Which I am fine with  - if you give me a time line to say LDPv6,
> SR-OSPFv3 and SR-ISISv6 will be available on X date, I can manage my
> operation and expectations accordingly.
> But if you say, "No LDPv6, no SR-OSPFv3, no SR-ISISv6... only SRv6", then
> that's an entirely different issue.
> The good news is there currently is choice on the matter, but upending
> hundreds or thousands of boxes to prove that point should really be a last
> resort, as there are more pressing things we all have to deal with.
Hence our current strategy is to stay on IPv4 control-plane (and IPv4 management plane) as it suits, and for the foreseeable future will suite, all our needs (which are to transport v4&v6 data packets via L2&L3 MPLS VPN services), there are simply more important projects than to experiment with v6 control-plane, like for instance perfecting/securing the v6 customer facing services (delivered over the underlying v4 signalled MPLS infrastructure, that no customer really cares about). 

But I understand your frustrations case it seems like you're taking the bullet for us late adopters and in a sense you are, cause say in 10 years from now when I decide to migrate to v6 control-plane and management-plane as then it might be viewed as common courtesy, it will be all there on a silver plate waiting for me allowing for a relatively effortless and painless move. All thanks to you fighting the good fight today.    

> >  Yes you're right in acknowledging that we're not living in a perfect world
> and that choices are limited, but it's been like that since ever yet we
> managed to thrive by analysing our options and striving for optimal strategies
> year by year.
> We can thank NAT44, CIDR, DHCP and PPPoE for that strategy over the years
> :-).
> IPv6 is the future, and at some point, we'll have to stop hiding from it.
And I'd say the future is now, cause there is an actual need for v6 services. 
But need for v6 control & management plane? - It's not like operators are losing business opportunities not having that. (they might even be viewed as conservative->stable, which might be preferred by some customers). 


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