Troubleshooting guide

8-33
ATM and Layer 3 Switch Router Troubleshooting Guide
OL-1969-01
Chapter 8 Troubleshooting Tag and MPLS Switching Connections
Troubleshooting MPLS VPN
valid cached adjacency
tag rewrite with AT1/0/1, point2point, tags imposed: {51(vcd=51) 20}
105.0.0.0/8, version 16, cached adjacency 14.0.0.2
0 packets, 0 bytes
tag information set
local tag: 19
via 14.0.0.2, 0 dependencies, recursive
next hop 14.0.0.2, GigabitEthernet2/0/1 via 14.0.0.2/32
valid cached adjacency
tag rewrite with Gi2/0/1, 14.0.0.2, tags imposed: {}
172.20.0.0/16, version 17, cached adjacency 14.0.0.2
0 packets, 0 bytes
tag information set
local tag: 20
via 14.0.0.2, 0 dependencies, recursive
next hop 14.0.0.2, GigabitEthernet2/0/1 via 14.0.0.2/32
valid cached adjacency
tag rewrite with Gi2/0/1, 14.0.0.2, tags imposed: {}
224.0.0.0/24, version 2, receive
255.255.255.255/32, version 1, receive
8540-ATM-PE2#
Step 5 Veri fy:
• That the tag information set with the local tag field confirms that the labels are used effectively.
• That the fast tag rewrite field displays a stack of (at least) two labels that are used for VPN
destinations.
Pinging VPN Connection Neighbors
Follow these steps to verify the MPLS VPN connections:
Note Before establishing an MPLS VPN, you must be able to ping, for example, the “8540-PE1” ATM
switch router (111.0.1.18) from “8540-PE2” (111.0.1.1), and vice-versa. (See Figure 8-5.)
To see if the VRF works, use the ping command.
Note If you are checking a provider edge ATM switch router, you must add the specific VRF name.
Follow these steps to verify the neighbor MPLS interface connections:
Step 1 Enter the ping command to verify that the connection is up between the provider-edge ATM switch
routers and the customer-edge routers
8540-PE2# ping vrf Red 222.2.2.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 222.2.2.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms
8540-PE2#
This ping command example confirms the connections, shown in Figure 8-5.