Performing MPLS Ping/Traceroute Tests
After completing the configuration, you can run the ping command to check the connectivity between a sender and a destination address. You can also run the tracert command to view the gateways, through which the packets sent by the sender to a destination address pass.
After completing the VPN configuration, you can run the ping command with the -vpn-instance vpn-instance-name parameter configured on the PE to check the connectivity between the PE and CE in the same VPN. If the ping fails, run the tracert command with the -vpn-instance vpn-instance-name parameter to diagnose network faults.
If multiple interfaces on the PE are bound to the same VPN, run the ping or tracert with the -a source-ip-address parameter configured on a local PE to ping the CE. If no source IP address is specified, the PE selects the lowest IP address of an interface bound to the VPN as the source IP address for the Internet Control Message Protocol (ICMP) messages. If the routing table of the CE does not contain the route to the selected IP address, the CE discards the returned ICMP message.
By default, for an MPLS TTL timeout packet with a single label, the FW returns an ICMP message over a local public network route. The public network routing table of the ASBR PE, however, contains no VPN route. As a result, an ICMP message sent or returned by the ASBR PE is discarded.
In this case, a ping is successful.
You can run the commands listed in Table 1 to check the connectivity of the BGP/MPLS IP VPN network.
Operation |
Command |
|---|---|
Check the connectivity between the sending device and destination address. |
ping [ ip ] [ -a source-ip-address | -c count | -d | { -f | ignore-mtu } | -h ttl-value | { [ -nexthop nexthop-address ] [ -i interface-type interface-number ] | -si source-interface-type source-interface-number } | -m time | -n | -name | -p pattern | -q | -r | { -s packetsize | -range [ min min-size | max max-size | step step-size ] * } | -system-time | -t timeout | { -tos tos-value | -dscp dscp-value } | -v | -vpn-instance vpn-instance-name | -ri | -8021p 8021p-value ] * host [ ip-forwarding ] |
Check the gateways through which the packets sent by the sending device to the destination address pass. |
tracert [ -a source-ip-address | -f first-ttl | -m max-ttl | -name | -p port | -q nqueries | -s packet-size | -v | -vpn-instance vpn-instance-name [ pipe ] | -w timeout ] * host |