[c-nsp] Maximum number of VRF-Lite instances in ISR G2 routers

[Peter Rathlev]

On Wed, 2011-07-13 at 10:01 +0200, Matteo Castelli ML wrote:
> I am starting a project to implement VRF-lite for some customers,
> does anybody know (or have a link to some Cisco documentation) the
> maximum number of VRF-lite instances in the different ISR G2 routers
> models of Cisco?

I tried creating a bunch of VRFs on a plain 2801 with 128M RAM running
12.4(24)T3 Enterprise Base. It's not a G2, but the results should not be
worse.

It seems that the number of VRFs is only limited by memory. Statistics
for processor memory:
 
 #VRFs   Total(b)  Used(b)  Free(b) Lowest(b) Largest(b)
   300   55234624 33762740 21471884  21387108   21400832
   400   55234624 38923612 16311012  16234112   16255268
   500   55234624 44236524 10998100  10934664   10919836
   600   55234624 49404172  5830452   5754544    5763496
   700   55234624 54614228   620396    557736     555396

After the 700th VRF the box logged this:

 005493: Jul 13 10:26:52.299 CEST: %AAA-3-ACCT_LOW_MEM_TRASH: AAA unable
to handle accounting requests due to insufficient processor memory and
could be trashing the queued accounting records

Keep in mind that this is a lab test, no traffic et cetera.

My guess is that the raw number of VRFs supported on a G2 would be
something in the ballpark of 1000 or more. I would also guess that the
limiting factor would be forwarding performance before number of VRFs. I
don't have a G2 readily available to test though.

The VRFs were created as:

 ip vrf test<number>
  rd 1:<number>
 !

-- 
Peter