virtual aggregation in IETF

Joel Jaeggli joelja at
Sun Jul 20 16:27:41 UTC 2008

Paul Francis wrote:
> Gang,
> I have submitted an internet-draft to the IDR group on virtual aggregation
> (VA) (
> This draft suggests a few changes to routers that allow operators to control
> the size of their FIBs, shrinking them by 5x or 10x quite easily.  This would
> extend the lifetime of routers that are constrained by FIB size.
> There has been a lively discussion of this on the IDR mailing list, including
> a suggestion that FIB reduction is more important for lower tier ISPs (tier
> 2, tier 3...) than for tier 1 ISPs.  Unfortunately I don't think that people
> from smaller ISPs pay much attention to the IDR mailing list, so they are not
> being represented in this discussion.

Software switched routers have little pressure on fib limitions. For a 
certain class of application the software switched edge router is in a 
much better position to accommodate fib growth than a device with a 
fixed sized cam.

If you're in the business of shopping for sup-2s on ebay you'll probably 
  see significant benefits in fib reduction.

> So I'm looking for input from folks who think that FIB reduction helps them,
> so as to better understand their requirements.
> Any help is much appreciated.
> Thanks,
> PF

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