IP in IP

English Alternative forms IP-in-IP Etymology Contraction of IP in IP encapsulation used in rfc:2003, which specified the protocol. Noun - en Internet A protocol for sending IP packets over an existing IP network. en IP in IP is an unusual mechanism: not only does it use two network layers, it uses the same protocol on both. en Although IP in IP incurs an overhead, as the size of the headers is doubled, it may allow you to create a connection between two hosts that would otherwise be blocked by a firewall. See also