[c-nsp] Same PE as global next-hop for VRF route

Everton da Silva Marques everton at lab.ipaccess.diveo.net.br
Wed Nov 16 08:27:43 EST 2005

On Wed, Oct 26, 2005 at 04:26:52PM +0100, Ian Dickinson wrote:
> Everton da Silva Marques wrote:
> > Would the ability to use a global address of the
> > local PE as global next-hop for VRF routes be
> > a reasonable feature request?
> I'm not sure how CEF would handle this, but I'd like this.
> E.g. when I use
>  ip route vrf VRFNAME global
> remote traffic can reach all of except the local
> PE's own interface.  To get full coverage, I need 2 nodes doing
> this function.

It seems Juniper supports the feature we're looking
for, according the document below. Is anyone able
to convince Cisco of its usefulness? :-)

  Providing Internet Access to and from VPNs
  Configuring a Fallback Global Option

The second solution is to use the fallback global option
on the PE-CE IP interface. If you have configured this
option, the PE router simultaneous performs two
different lookups when a packet arrives from the CE
router. One lookup is in the IP routing table of the
VRF; the other lookup is in the IP routing table of
the parent VR. 

If BGP finds a route in the VRF context, it uses that
route. If BGP does not find a route in the VRF context
but does find a route in the VR context, it falls back
on the global route in the parent VR. BGP drops the
packet if it doesn't find a route in either context.

To enable fallback global on a PE-CE IP interface:

host1:pe1(config)#interface atm2/0.11
host1:pe1(config-if)#ip vrf forwarding pe11 fallback global
host1:pe1:pe11(config-if)#atm pvc 11 0 11 aal5snap
host1:pe1:pe11(config-if)#ip address

More information about the cisco-nsp mailing list