I am curious to understand how copper Ethernet keepalive are used and work between a host or router and a switch? Cisco default keepalive is 10 seconds with 3 or 5 retries, does this mean 30s or 50s to detect copper link failure?? I may miss something, thanks for your help. The link failure detection doesn't occur with optical links because hardware detection (Rx < Rx_min) is much more real time than keepalive timeout expiration. R/ Manu