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BGP Error?

jokerfmj1
Level 1
Level 1

So I'm trying to trace out this route in my environment running MPLS/MP-BGP. When I check for the route the switch returns a good route, but when I try to find the RD using show ip bgp the switch tells me there are no routes. I am wondering if this could be related to bug CSCum05295?

 

See the below output:

 

 

Core-Switch# sho ip ro vrf APP 10.10.10.200
IP Route Table for VRF "APP"
'*' denotes best ucast next-hop
'**' denotes best mcast next-hop
'[x/y]' denotes [preference/metric]
'%<string>' in via output denotes VRF <string>

0.0.0.0/0, ubest/mbest: 1/0
    *via 10.0.10.10%default, [200/51456], 7w4d, bgp-65400, internal, tag 65400,  (mpls-vpn)



Core-Switch# sho ip bgp vrf APP 10.10.10.200
BGP routing table information for VRF APP, address family IPv4 Unicast
BGP routing table entry for 10.10.10.128/25, version 0
Paths: (0 available, best #0)
Flags: (0x090000) on no lists, is not in urib, is not in HW, 
  vpn: version 0, (0x910000) on no lists

  VRF advertise information:
  Path-id 1 not advertised to any peer

  VPN AF advertise information:
  Path-id 1 not advertised to any peer

 

 

 

1 Reply 1

Giuseppe Larosa
Hall of Fame
Hall of Fame

Hello Jokerfmj1,

from the output of show ip route vrf APP we see that there is not a matching specific entry  for the prefix as you can see it is matching a default route 0.0.0.0/0 learned by VRF default (that may mean global routing table)

 

0.0.0.0/0, ubest/mbest: 1/0
    *via 10.0.10.10%default, [200/51456], 7w4d, bgp-65400, internal, tag 65400,  (mpls-vpn)

 So this is not in contrast with the output of show ip bgp vrf APP that says that no specific MP BGP route exists for the prefix 10.10.10.128/25.

 

Without knowing more about your network scenario we cannot say more.

It looks like you are leaking a default route 0.0.0.0/0 from vrf default into vrf APP from first output.

The only strange thing about the second output is that you haven't specified the prefix and prefix length so it is not clear how the system knows about prefix 10.10.10.128/25.

There is a remote PE sending the prefix 10.10.10.128/25 with a route target extcommunity value that is accepted imported in vrf APP in the local node ?

You coul check this with

show ip bgp vpnv4 all 10.10.10.128/25

 

Hope to help

Giuseppe