Configuring an IP tunnel

Prerequisites

An enabled layer 3 interface with an IP address assigned to it, created with the command interface.

Procedure
  1. Create an IP tunnel with the command interface tunnel .
  2. Set the IP address for the tunnel. For a GRE tunnel, enter the command ip address ip address. For an IPv6 in IPv4 or an IPv6 in IPv6 tunnel, enter the command ipv6 address.
  3. Set the source IP address for the tunnel. For a GRE or an IPv6 in IPv4 tunnel, enter the command source ip. For an IPv6 in IPv6 tunnel, enter the command source ipv6.
  4. Set the destination IP address for the tunnel. For a GRE or an IPv6 in IPv4 tunnel, enter the command destination ip . For an IPv6 in IPv6 tunnel, enter the command destination ipv6.
  5. Optionally, set the TTL (hop count) for the tunnel with the command ttl.
  6. Optionally, set the MTU for the tunnel with the command ip mtu.
  7. Optionally, add a description to the tunnel with the command description.
  8. By default, the tunnel is attached to the default VRF. Attach it to a different VRF with the command vrf attach.
  9. Enable the tunnel with the command no shutdown.
  10. Review tunnel settings with the command show interface tunnel.

Example

This example creates the following configuration:

  • Creates GRE tunnel 33.
  • Set the tunnel IP address to 10.10.20.209/24.
  • Sets the tunnel source IP address to 10.10.10.1.
  • Sets the tunnel destination IP address to 10.10.10.2.
  • Enables the tunnel. 
switch(config)# interface tunnel 33 mode gre ipv4
switch(config-gre-if)# ip address 10.10.20.209/24
switch(config-gre-if)# source ip address 10.10.10.1
switch(config-gre-if)# destination ip address 10.10.10.2
switch(config-gre-if)# no shutdown