Troubleshooting Gre - HP 5920 Series Configuration Manual

0 packets input, 0 bytes, 0 drops
0 packets output, 0 bytes, 0 drops
# From Switch B, ping the IP address of VLAN-interface 100 on Switch A.
[SwitchB] ping -a 10.1.3.1 10.1.1.1
PING 10.1.1.1 (10.1.1.1) from 10.1.3.1: 56 data bytes
56 bytes from 10.1.1.1: icmp_seq=0 ttl=255 time=2.000 ms
56 bytes from 10.1.1.1: icmp_seq=1 ttl=255 time=1.000 ms
56 bytes from 10.1.1.1: icmp_seq=2 ttl=255 time=1.000 ms
56 bytes from 10.1.1.1: icmp_seq=3 ttl=255 time=0.000 ms
56 bytes from 10.1.1.1: icmp_seq=4 ttl=255 time=1.000 ms
--- 10.1.1.1 ping statistics ---
5 packet(s) transmitted, 5 packet(s) received, 0.0% packet loss
round-trip min/avg/max/stddev = 0.000/1.000/2.000/0.632 ms
The output shows that Switch B can successfully ping Switch A.

Troubleshooting GRE

The key to configuring GRE is to keep the configurations consistent. Most faults can be located by using
the debugging gre or debugging tunnel command. This section analyzes one type of fault for illustration,
with the scenario shown in
Figure 83 Network diagram
Symptom
The interfaces at both ends of the tunnel are configured correctly and can ping each other, but Host A
and Host B cannot ping each other.
Analysis
It may be because that Device A or Device C has no route to reach the peer network.
Solution
Execute the display ip routing-table command on Device A and Device C to view whether Device
1.
A has a route over tunnel 0 to 10.2.0.0/16 and whether Device C has a route over tunnel 0 to
10.1.0.0/16.
If such a route does not exist, execute the ip route-static command in system view to add the route.
2.
Take Device A as an example:
[DeviceA] ip route-static 10.2.0.0 255.255.0.0 tunnel 0
Figure 83.
190