Utility of a Tunnel GRE ?

[BicMac080]

Hello,

Is there somebody who could inform me on the utility of a basic tunnel GRE (without ipsec encryption) between 2 points, with IP like transported protocol, because as I see we need a routing on the backbone to reach the 2 IP addresses ends of the tunnel, in addition to one routing to join the tunnels sources and destination of the tunnel.

Thanks

 

[rodolfopereira]

Is Usefull when you have IP overlap

 

[lgarner]

One thing it allows is for the two GRE endpoints to appear as neighbors for purposes of dynamic routing protocols like EIGRP.

 

[jneiberger]

It's also helpful if you need to run a non-IP protocol over a network that only supports IP. Or, you can use it to route multicast over networks that don't support multicast by turning on multicast routing in your tunnels.