[c-nsp] Different behaviour for static route on different IOS?

[Gert Doering]

Hi,

On Wed, Feb 16, 2005 at 10:51:17AM +0100, Oliver Boehmer (oboehmer) wrote:
> > Indeed, it's not "classful", but a more generic check "if the route
> > prefix *and* the gateway IP are part of the *same* supernet route
> > (/16, default route, ...) --> suppress recursive static route".
> 
> coz it wouldn't make much sense, would it?
> 
> you learn 192.168/16 via POS0/0, and you enter a static route for
> 192.168.20/24 pointing to a nexthop within 192.168/16, all traffic to
> 192.168/16 (including 192.168.20/24) would still go out POS0/0. 

Well.  There is something to be said for this...

> because it adds routing information.. I don't really find this
> surprising..

... but usually the box doesn't check "does it add any useful information
if I put this route into service" either.

Like in:

  ip route 192.168.0.0 255.255.0.0 pos0/0
  ip route 192.168.20.0 255.255.255.0 pos0/0

-> you'll see *both* routes in the RIB and FIB, even if the second route
"doesn't add routing information" either...

But whatsoever - I'm not trying to criticise (today :) ), I was just
explaining my surprise, and now I have understood what's going on.

gert
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Gert Doering - Munich, Germany                             gert at greenie.muc.de
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