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Cisco Router and Security Device Manager Version 2.2 User’s Guide
OL-4015-08
Chapter4 Edit Interface/Connection
Add or Edit GRE Tunnel'
Tunnel Source
Select the interface that the tunnel will use. This interface must be reachable from
the other end of the tunnel; therefore, it must have a public, routeable IP address.
Tunnel Destination
The tunnel destination is the interface on the router at the other end of the tunnel.
Select whether you will specify an IP address or a host name, and then enter that
information. If you selected IP address, provide the IP addr ess and subnet mask
in dotted decimal format; for example, 192.168.20.1 and 255.255.255.0.
Make sure that this address or host name is reachable using the ping command;
otherwise, the tunnel will not be created properly.
Tunnel IP Address
Enter the IP address of the tunnel in dotted decimal format; for example,
192.168.20.1. For more information, refer to IP Addresses and Subnet Masks.
GRE Keepalive
Check this box if you want the router to send GRE keepalives. Specify the
interval, in seconds, that keepalives will be sent, and the waiting period, in
seconds, between retries.
Maximum Transmission Unit
Enter the maximum transmission unit (MTU) size. If you want the size adjusted
to a lower value when the adjustment would avoid packet fragmentation, click
Adjust MTU to avoid fragmentation.
Bandwidth
Click to specify the bandwidth for this tunnel in kilobytes.