[c-nsp] Advertising private network in iBGP

Marco Matarazzo marmata at libero.it
Thu Dec 16 08:23:35 EST 2004


> Thanks Marco,
>
> Finally i tried and its working but one more query,
>
> When i tried with
> network 172.22.0.0 mask 255.255.0.0
>
> and matching prefix-list and route its not getting advertised.
> What would be the problem in this.

Well that's strange...

Check the following:

1) no-synchronization on the bgp router process.
2) a route exists covering the whole network (an ip route 172.22.0.0
255.255.0.0 null0 will do the trick)
3) prefix-list is correctly configured
4) route-maps are correctly configured
5) last but not least: check that the other peer accepts the route with the
proper prefix-list inbound

The output of a

sh ip bgp 172.22.0.0
sh ip route 172.22.0.0
sh ip bgp ne (your iBGP neighbor) adv
your outbound prefix lists and routemaps.

could also help!

Cheers!
]\/[arco

>
> Regards
> Tejal Shah
>
>
> On Wed, 15 Dec 2004 15:19:40 +0100, Marco Matarazzo <marmata at libero.it>
wrote:
> > Hi Prit,
> >
> > > I m trying to advertise ip block 10.12.5.0/24 & 10.12.9.0/24 in my BGP
> > > session but it is not getting advertise.
> > >
> > > router bgp 100
> > > network 10.12.5.0
> > > neighbor 2.2.2.2 prefix-list go-out out
> > >
> > > ip route 10.12.5.0 255.255.255.0 1.1.1.1
> > >
> > > ip prefix-list go-out permit 10.12.5.0/24
> > >
> > > But the network 10.12.5.0 is not appering in my advertised routes on
> > > this router.
> >
> > try:
> >
> > network 10.12.5.0 mask 255.255.255.0
> >
> > and it should work.
> > Since you're omitting the netmask in the network statement, Cisco keeps
the
> > 'natural' network mask. You don't have a route for the full /8, only to
the
> > more specific /24, and the route won't be advertised this way.
> >
> > Cheers,
> > ]\/[arco
> >
> > >
> > > Is there any special command required to enable this.
> > >
> > > Regards
> > > Prit
> > > _______________________________________________
> > > cisco-nsp mailing list  cisco-nsp at puck.nether.net
> > > https://puck.nether.net/mailman/listinfo/cisco-nsp
> > > archive at http://puck.nether.net/pipermail/cisco-nsp/
> >
> >



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