This table contains the extended keepalive parameters. The Table is per interface. Although for the first phase it will be relevant for WAN Fast Ethernet Port. But may be available in the future for interface. The keepalive on specific interface may bring it to line protocol down according the results. The main idea is to check certain IP that if not responding then the link/route may be down and therefore the interface is bring to line protocol down. In this case there still be sent extended keepalive packets in order to check whether the line protocol is up.