Technical Documentation

Pinging the Directly Connected CE Routers from the PE Routers

From the VPN and loopback interfaces on the PE routers, you can ping the VPN interface on the directly connected CE router. Troubleshooting Layer 3 VPNs Using ping and traceroute shows the topology referenced in the following examples:

Pinging the VPN Interface on Router CE1 from Router PE1

From the VPN interface on the PE router, you can ping the VPN or loopback interface on the directly connected CE router.

From the VPN interface on Router PE1 (VPN1), ping the VPN interface, fe-1/1/0.0, on Router CE1:

user@vpn1> ping 192.168.192.4 interface
fe-1/1/0.0 local 192.168.192.1 count 3

PING 192.168.192.4 (192.168.192.4): 56 data bytes
64 bytes from 192.168.192.4: icmp_seq=0 ttl=255 time=0.866 ms
64 bytes from 192.168.192.4: icmp_seq=1 ttl=255 time=0.728 ms
64 bytes from 192.168.192.4: icmp_seq=2 ttl=255 time=0.753 ms
--- 192.168.192.4 ping statistics ---
3 packets transmitted, 3 packets received, 0% packet loss
round-trip min/avg/max/stddev = 0.728/0.782/0.866/0.060 ms

Pinging the Loopback Interface on Router CE1 from Router PE1

From the VPN interface on Router PE1 (VPN1), ping the loopback interface, 10.255.10.4, on Router CE1:

user@vpn1> ping 10.255.10.4 interface
fe-1/1/0.0 local 192.168.192.1 count 3

PING 10.255.10.4 (10.255.10.4): 56 data bytes
64 bytes from 10.255.10.4: icmp_seq=0 ttl=255 time=0.838 ms
64 bytes from 10.255.10.4: icmp_seq=1 ttl=255 time=0.760 ms
64 bytes from 10.255.10.4: icmp_seq=2 ttl=255 time=0.771 ms
--- 10.255.10.4 ping statistics ---
3 packets transmitted, 3 packets received, 0% packet loss
round-trip min/avg/max/stddev = 0.760/0.790/0.838/0.034 ms

Using traceroute from Router PE1 to Router CE1

To determine the path from the VPN interface on Router PE1 to the VPN and loopback interfaces on Router CE1, respectively, use the following traceroute commands:

user@vpn1> traceroute 10.255.10.4 interface
fe-1/1/0.0 source 192.168.192.1

traceroute to 10.255.10.4 (10.255.10.4) from 192.168.192.1, 30 hops max, 40 byte packets
 1  vpn4.isp-core.net (10.255.10.4)  0.842 ms  0.659 ms  0.621 ms
user@vpn1>  traceroute 192.168.192.4 interface fe-1/1/0.0 source 192.168.192.1    
traceroute to 192.168.192.4 (192.168.192.4) from 192.168.192.1, 30 hops max, 40 byte packets
 1  vpn4-fe-112.isp-core.net (192.168.192.4)  0.810 ms  0.662 ms  0.640 ms

Pinging the VPN Interface on Router CE2 from Router PE2

From the VPN interface on Router PE2 (VPN2), ping the VPN interface, t3-0/0/3.0, on Router CE2:

user@vpn2> ping 192.168.193.5 interface
t3-0/0/3.0 local 192.168.193.2 count 3

PING 192.168.193.5 (192.168.193.5): 56 data bytes
64 bytes from 192.168.193.5: icmp_seq=0 ttl=255 time=0.852 ms
64 bytes from 192.168.193.5: icmp_seq=1 ttl=255 time=0.909 ms
64 bytes from 192.168.193.5: icmp_seq=2 ttl=255 time=0.793 ms
--- 192.168.193.5 ping statistics ---
3 packets transmitted, 3 packets received, 0% packet loss
round-trip min/avg/max/stddev = 0.793/0.851/0.909/0.047 ms

Pinging the Loopback Interface on Router CE2 from Router PE2

From the VPN interface on Router PE2 (VPN2), ping the loopback interface, 10.255.10.5, on Router CE2:

user@vpn2> ping 10.255.10.5 interface
t3-0/0/3.0 local 192.168.193.2 count 3

PING 10.255.10.5 (10.255.10.5): 56 data bytes
64 bytes from 10.255.10.5: icmp_seq=0 ttl=255 time=0.914 ms
64 bytes from 10.255.10.5: icmp_seq=1 ttl=255 time=0.888 ms
64 bytes from 10.255.10.5: icmp_seq=2 ttl=255 time=1.066 ms
--- 10.255.10.5 ping statistics ---
3 packets transmitted, 3 packets received, 0% packet loss
round-trip min/avg/max/stddev = 0.888/0.956/1.066/0.079 ms

Using traceroute from Router PE2 to Router CE2

To determine the path from the VPN interface on Router PE2 to the VPN and loopback interfaces on Router CE2, respectively, use the following traceroute commands:

user@vpn2> traceroute 10.255.10.5 interface
t3-0/0/3.0 source 192.168.193.2

traceroute to 10.255.10.5 (10.255.10.5) from 192.168.193.2, 30 hops max, 40 byte packets
 1  vpn5.isp-core.net (10.255.10.5)  1.009 ms  0.677 ms  0.633 ms
user@vpn2>  traceroute 192.168.193.5 interface t3-0/0/3.0 source 192.168.193.2  
traceroute to 192.168.193.5 (192.168.193.5) from 192.168.193.2, 30 hops max, 40 byte packets
 1  vpn5-t3-003.isp-core.net (192.168.193.5)  0.974 ms  0.665 ms  0.619 ms