[c-nsp] Cisco BGP Running on VRF?

Murphy, William William.Murphy at uth.tmc.edu
Wed Oct 1 15:09:05 EDT 2008


I am saying that there is MPLS going on because "show platform hardware
capacity pfc" is showing a lot of TCAM being consumed for MPLS.  I tried
the commands you mentioned and those commands are not even available in
the CLI.  I did "show ?" and mpls is not in there.  According to Cisco
MPLS is not supported under VSS, but perhaps something in the hardware
or CEF is still allocating TCAM?  Maybe someone from Cisco on this list
will have the answer...  Thanks for your help...

L3 Forwarding Resources
             FIB TCAM usage:                     Total        Used
%Used
                  72 bits (IPv4, MPLS, EoM)     933888      810511
87%
                 144 bits (IP mcast, IPv6)       57344           7
1%

                     detail:      Protocol                    Used
%Used
                                  IPv4                      540371
58%
                                  MPLS                      270139
29%
                                  EoM                            1
1%

                                  IPv6                           1
1%
                                  IPv4 mcast                     3
1%
                                  IPv6 mcast                     3
1%

-----Original Message-----
From: Peter Rathlev [mailto:peter at rathlev.dk] 
Sent: Wednesday, October 01, 2008 2:17 AM
To: Murphy, William 
Cc: cisco-nsp at puck.nether.net
Subject: Re: [c-nsp] Cisco BGP Running on VRF?

Hi Bill,

On Tue, 2008-09-30 at 17:50 -0500, Murphy, William wrote:
> I have a Cat6506 VSS720-3C-XL switch on which I have configured BGP on
> a VRF using  "address-family ipv4 unicast vrf internet".  I am getting
> BGP routes and all appears well but I can only display BGP info by
> using "show ip bgp vpnv4 ..." commands.  I didn't intend to run VPNV4
> and it appears the switch has ignored my address-family ipv4
> statement.  Can someone explain what's going on here?

That command is _the_ way to show the VRFs BGP table. Remember that VRF
comes from the MP-BGP world, and over there belongs under VPNv4. It's
just syntax though, you don't run VPNv4 if you haven't configured the
"address-family vpnv4".

> It also seems like the switch is creating MPLS labels for all my
routes
> even though I didn't specifically configure any MPLS or tag switching
> commands.  Any words of wisdom or advice would be appreciated...

Are you sure you don't have any MPLS related commands? On a "clean"
switch i get:

R1# sh mpls ldp bin
TIB not enabled

R1#sh mpls for
Tag switching is not operational.
CEF or tag switching has not been enabled.
No TFIB currently allocated.
R1#

(This is SXD though, which was there. It might be different on newer
software.)

If you have any MPLS command configured, the allocation is expected. The
switch will always allocate labels for anything in the FIB, also is e.g.
no interfaces are configured for MPLS. (That is unless you're lucky and
can use Label Allocation Filtering, http://tinyurl.com/224kv8. On a 6500
you're not at the moment.)

Regards,
Peter




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