[c-nsp] aggregate lfib entry - what is the actual prefix ?

[Aaron]

Ah, thanks.  I just added some more aggregates into vrf test within bgp and I see how they all use same label.

 

Aaron

 

 

 

RP/0/0/CPU0:R8-xr#sh mpls for | in test

16082  Aggregate   test: Per-VRF Aggr[V]   \

                                      test                         0

 

RP/0/0/CPU0:R8-xr#sh bgp vpnv4 uni lab | in "16082|Network"

Fri Feb 13 10:07:44.074 UTC

   Network            Next Hop        Rcvd Label      Local Label

*> 172.16.0.0/16      0.0.0.0         nolabel         16082

s> 172.16.1.0/24      0.0.0.0         nolabel         16082

s> 172.16.2.0/24      0.0.0.0         nolabel         16082

*> 172.17.0.0/16      0.0.0.0         nolabel         16082

s> 172.17.1.0/24      0.0.0.0         nolabel         16082

s> 172.17.2.0/24      0.0.0.0         nolabel         16082

*> 192.168.0.0/16     0.0.0.0         nolabel         16082

* i                   10.0.0.5        23              16082

 

 

*** Another PE on other side of network....

 

R1#sh bgp vpnv4 unicast all labels | in Network|16082

   Network          Next Hop      In label/Out label

   172.16.0.0       10.0.0.8        nolabel/16082

   172.17.0.0       10.0.0.8        nolabel/16082

   192.168.0.0/16   10.0.0.8        nolabel/16082

   172.16.0.0       10.0.0.8        nolabel/16082

                    10.0.0.8        nolabel/16082

   172.17.0.0       10.0.0.8        nolabel/16082

                    10.0.0.8        nolabel/16082

   192.168.0.0/16   10.0.0.8        nolabel/16082

                    10.0.0.8        nolabel/16082

 

 

 

 

From: Adam Vitkovsky [mailto:avitkovsky at gammatelecom.com] 
Sent: Friday, February 13, 2015 10:05 AM
To: Lukas Tribus; Aaron; cisco-nsp at puck.nether.net
Subject: RE: [c-nsp] aggregate lfib entry - what is the actual prefix ?

 

Lukas is right,
Think of it this way:
Consider data-plane perspective: 
When a packet arrives on the PE destined to a 192.168.1.1 IP address -it's not going to be switched to where the 192.168.0.0/16 points to as it would get dropped. 
Instead an additional FIB lookup in the VRF is needed to find out which interface to use in order to forward the packet.

adam
> -----Original Message-----
> From: cisco-nsp [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of
> Lukas Tribus
> Sent: 13 February 2015 15:03
> To: Aaron; cisco-nsp at puck.nether.net
> Subject: Re: [c-nsp] aggregate lfib entry - what is the actual prefix ?
> 
> > Are you sure it doesn't map to a particular prefix ? I just found this.
> > This seems to be what it maps to...the aggregate route that I config'd
> > within bgp vrf test.
> 
> Aggregate routes will point to *the* aggregate vrf label, yes. But you can
> have many aggregates and they all will point to the very same label.
> 
> The aggregate label may only have been created because of your aggregate
> route, but that doesn't mean its per aggregate prefix. Its per vrf, really.
> 
> 
> Lukas
> 
> 
> _______________________________________________
> cisco-nsp mailing list cisco-nsp at puck.nether.net
> https://puck.nether.net/mailman/listinfo/cisco-nsp
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