Displaying and Debugging GRE 641
By default, the tunnel interface to synchronize datagram sequence numbers is
disabled.
Displaying and Debugging GRE To view the working status of the tunnel interface, use the display command in all views.
Tabl e 694 Display and Debug GRE
GRE Configuration Example
Application of IP-over-IP
GRE VPN should be built across the WAN for the operation of Novell IPX's two subnets
group1 and group2. It can be implemented by using GRE.
PC A communicates with PC B in GRE tunneling mode in the Internet. Router A
and Router B are two ends of the GRE tunnel, while Router C is located in the GRE
tunnel.
Figure 204 Networking diagram of GRE application
1Configure PC A and PC B:
aConfigure the IP address of PC_A to 10.110.24.100, add a default gateway in
the network attribute (i.e., default route), or use the following command in
DOS mode.
C:\WINDOWS> route add 0.0.0.0 mask 0.0.0.0 10.110.24.1
bConfigure the IP address of PC_B to 30.110.1.200, add a default gateway in
the network attribute (i.e., default route), or use the following command in
DOS mode.
C:\WINDOWS> route add 0.0.0.0 mask 0.0.0.0 30.110.1.1
2Configure Router A:
aConfigure the IP address of Serial0 interface.
[RouterA] interface serial 0
[RouterA-Serial0] ip address 10.1.1.1 255.255.255.0
Disable tunnel interface to synchronize
sequence numbers. undo gre sequence-datagrams
Operation Command
Display the working status of tunnel
interface. display interfaces tunnel [
tunnel-number ]
Router B
Router C
PC A PC B
Router A
10.110.24.100 30.110.1.200
tunnel
E0 S0 S0 S1 S0 E0
Internet
10.110.24.1
10.1.1.2 20.1.1.1 20.1.1.2
10.1.1.1
30.110.1.1