1. Scheme used by Cisco routers to cause a host to treat an interface as if it were up and supporting a session. The router spoofs replies to keepalive messages from the host in order to convince that host that the session still exists. Spoofing is useful in routing environments such as DDR, in which a circuit-switched link is taken down when there is no traffic to be sent across it in order to save toll charges. See also DDR. 2. The act of a packet illegally claiming to be from an address from which it was not actually sent. Spoofing is designed to foil network security mechanisms such as filters and access lists.
A method of fooling network end stations into believing that keep-alive signals have come from and return to the host. Polls are received and returned locally at either end of the network and are transmitted only over the open network if there is a condition change.
This reduces network overload by reducing traffic on a WAN (such as signals that repeatedly state a device is alive). The router or bridge can tell a remote device that a LAN device is still powered on instead of the LAN device informing the remote device it is still powered on. Also see Bridge LAN Router Traffic WAN