nanog mailing list archives

Re: Devil's Advocate - Segment Routing, Why?


From: Mark Tinka <mark.tinka () seacom mu>
Date: Sun, 21 Jun 2020 09:56:05 +0200



On 20/Jun/20 22:00, Baldur Norddahl wrote:


I can't speak for the year 2000 as I was not doing networking at this
level at that time. But when I check the specs for the base mx204 it
says something like 32 VRFs, 2 million routes in FIB and 6 million
routes in RIB. Clearly those numbers are the total of routes across
all VRFs otherwise you arrive at silly numbers (64 million FIB if you
multiply, 128k FIB if you divide by 32). My conclusion is that scale
wise you are ok as long you do not try to have more than one VRF with
a complete copy of the DFZ.

I recall a number of networks holding multiple VRF's, including at least
2x Internet VRF's, for numerous use-cases. I don't know if they still do
that today, but one can get creative real quick :-).



More worrying is that 2 million routes will soon not be enough to
install all routes with a backup route, invalidating BGP FRR.

I have a niggling feeling this will be solved before we get there.

Now, whether we can afford it is a whole other matter.

Mark.

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