Enter tunnel interface configuration context, create a Tunnel interface if it does not exist, or delete a Tunnel interface or sub-interface

Enable the tunnel keepalive feature

Add a checksum to the GRE header of packets traveling through the tunnel

When a checksum is included on one endpoint, the receiving tunnel endpoint performs checksum validation on incoming packets and packets without a valid checksum are discarded.

Disables checksums

Set the destination address of the tunnel

Assign a DSCP value to packets traveling through the tunnel

The DSCP value is placed in the packet’s Carrier IP header. You can assign a DSCP value of from 0 to 63. If you do not assign a DSCP value, the DSCP value is copied from the packet’s original IP header.

Enable and set an ID key for the tunnel

Tunnel ID keys are used as a security device. The key must be set to the same value on the tunnel endpoints. Packets without the configured key must be discarded.

Disables key checking

Enable dynamic MTU discovery by the tunnel

Set the source address of the tunnel

Assign a TTL value to packets traveling through the tunnel

The TTL value is placed in the packet’s Carrier IP header. You can assign a TTL value of from 1 to 255. The default tunnel TTL value is 255.

Show interface configuration and statistics for a particular tunnel or all GRE tunnels

If the Tunnel interface is down, this command displays the MTU value as not available.