Gre Troubleshooting - 3Com 3C13636 Configuration Manual

3Com Router 3000 Ethernet Family
Configuration Guide
# Configure static route from 3Com2 to Group 1 via interface Tunnel2/0/0.
[3Com2] ip route-static 10.1.1.0 255.255.255.0 tunnel 2/0/0

3.5 GRE Troubleshooting

GRE configuration is relatively simple, except that you should pay more attention to the
consistency. Most errors can be located by executing the debugging tunnel command.
Here, only one type of error is analyzed, as shown in the following figure:
PC A
10.1.1.1/16
Figure 3-9 Troubleshooting example of GRE
Symptom 1: The interfaces at both ends of the tunnel are correctly configured and both
ends of the tunnel can "ping" each other successfully, but PC A and PC B fail to do so.
Troubleshooting: Perform the following steps:
In user view, perform the display ip route command on 3Com1 and 3Com2
respectively, making sure there is the route from interface Tunnel1/0/0 to
10.2.0.0/16 on Router 3Com1, and the route from interface Tunnel 2/0/0 to
10.1.0.0/16 on Router 3Com2.
If the needed static route do not exist in the output information of the above step,
perform the ip route command in system view to add it. Taking Router 3Com1 for
example, make the following configuration:
[3Com1] ip route-static 10.2.0.0 255.255.0.0 tunnel 1/0/0
Quidway1 Quidway3
Serial1/0/0
Tunnel1/0/0
Tunnel
3Com Corporation
3-11
Chapter 3 Configuration of GRE
Quidway2
PC B
Serial2/0/1
10.2.1.1/16
Tunnel2/0/0