Troubleshooting guide

8-37
ATM and Layer 3 Switch Router Troubleshooting Guide
OL-1969-01
Chapter 8 Troubleshooting Tag and MPLS Switching Connections
Troubleshooting MPLS ATM Connections
Follow these steps to verify the routing tables for MPLS VPN interface connections:
Step 1 To check routing tables or routing protocol databases, use the same commands you would use to check
the global routing table. For example, enter the show ip route vrf command with the VRF name to
display only the MPLS VPN connections.
8540-ATM-PE1# show ip route vrf 1
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
* - candidate default, U - per-user static route, o - ODR
P - periodic downloaded static route
Gateway of last resort is not set
B 101.0.0.0/8 [20/0] via 11.0.0.1, 1w1d
B 172.20.0.0/16 [20/0] via 11.0.0.1, 1w1d
C 11.0.0.0/8 is directly connected, GigabitEthernet2/0/1
B 14.0.0.0/8 [200/0] via 104.0.0.4, 1d20h
B 105.0.0.0/8 [200/0] via 104.0.0.4, 1d20h
8540-ATM-PE1#
Step 2 Check the destination for a particular address by entering the show ip route vrf command with the
VRF-name and the bgp routing protocol keyword.
8540-ATM-PE1# show ip route vrf 1 bgp
B 101.0.0.0/8 [20/0] via 11.0.0.1, 1w1d
B 172.20.0.0/16 [20/0] via 11.0.0.1, 1w1d
B 14.0.0.0/8 [200/0] via 104.0.0.4, 1d21h
B 105.0.0.0/8 [200/0] via 104.0.0.4, 1d21h
8540-ATM-PE1#
Border Gateway Protocol (BGP) is used between the PE routers and is necessary for inter-site
connectivity. In the following example, we use internal BGP (iBGP). You can also use external BGP
(eBGP) as an external routing protocol for Provider Edge-to-Customer Equipment route propagation.
Use the following commands to troubleshoot BGP:
Command Purpose
show ip bgp neighbors Shows detailed information on the BGP and TCP
connections to individual neighbors.
show ip bgp vpnv4 all Shows VPN address information from the BGP table.
show ip bgp vpnv4 vrf
VRF-name
Shows network layer reachability information (NLRI)
associated with the named VRF.
show ip bgp vpnv4 vrf VRF
name [ip-address]
Shows NLRI associated with the named VRF and a specific
connection.