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 :-).
Yes I once made a plan to have one VRF per transit provider plus a peering VRF. That way our BGP customers could have a session with each of those VRFs to allow them full control of the route mix. I would of course also need a Internet VRF for our own needs.
But the reality of that would be too many copies of the DFZ in the routing tables. Although not necessary in the FIB as each of the transit VRFs could just have a default route installed.
Regards,
Baldur