why am i in this handbasket? (was Devil's Advocate - Segment Routing, Why?)

Mark Tinka mark.tinka at seacom.mu
Mon Jun 22 14:47:53 UTC 2020


On 22/Jun/20 16:30, adamv0025 at netconsultings.com wrote:

> Not quite,
> The routing information is flooded by default, but the receivers will cherry
> pick what they need and drop the rest. 
> And even if the default flooding of all and dropping most is a concern -it
> can be addressed where only the relevant subset of all the routing info is
> sent to each receiver.
> The key takeaway however is that no single entity in SP network, be it PE,
> or RR, or ASBR...., ever needs everything, you can always slice and dice
> indefinitely.
> So to sum it up you simply can not run into any scaling ceiling with MP-BGP
> architecture.   

The only nodes in our network that have ALL the NLRI is our RR's.

Depending on the function of the egress/ingress router, the RR sends it
only what it needs for its function.

This is how we get away using communities in lieu of VRF's :-).

And as Adam points out, those RR's will swallow anything and everything,
and still remain asleep.

Mark.


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