Re: Concerns about ripv2 "subsumption"

[Dennis Ferguson <[e-mail]>]

Gary,

> I take it that the problem is that non-contiguous subnets will cause
> things to break, which is why they were illegal in RIP-1.  Well,
> they're illegal in RIP-2 by inheritance.  RIP-2 changes only what
> RIP-2 changes, everything else is the same.  I can put in some
> text explicitly forbidding partitioning when the RFC goes to Draft.

No, the problem is the subsumption rules in section 3.4, item 1, don't
work.  By default you need to advertise routes as you received them,
you can't in general combine several routes into a single route with
a shorter mask automatically without running the risk of breaking
something.

I think what needs to be done is to remove section 3.4, item 1, and
instead indicate that some routers will require the ability to have
subsumption configured for advertisements on a per-interface basis.
This is consistent with OSPF's handling of the issue at area boundaries,
and allows you to configure the same behaviour as RIP-1 at network
boundaries if you want it while allowing you to do other things if
you are all RIP-2+OSPF.

Dennis Ferguson