I am trying to grasp the purpose of the 'interface tunnel#' command, where # = the specific number of the interface I assign. I understand how to configure the interface and that I need a Tunnel Source & Destination address. I note that I would have a LAN Ip address and a WAN Ip address. I simply want to understand the relevance of the Tunnel Interface command as it clearly doesn't route traffic. My colleague explained that it is needed to allow the router to use the specific method of encapsulation e.g. GRE. Has anyone go a really good WWW site that they could point me at, or, provide a more detailed explanation. Thanks.