Perhaps someone can put this into perspective for me. This is an age old question that has arisen many times throughout the years and my web searches have failed to answer this. The host is visible in arp and shows incomplete, the host cannot be pinged. Sometimes the prob is a cable, sometimes a host route setting, sometimes an intermediary device. (Let me know if there are other known things that cause this). ca-santa-barbara-router#sh arp | i 70.169.191 Internet 71.169.191.209 0 Incomplete ARPA Internet 71.169.191.218 - 0018.731f.407d ARPA Ethernet1 My question is, how is it, that we get the IP address from the directly connected host into the ARP cache, but not the MAC address? We arp out for that IP, and the connected host is smart enough to reply that it has that IP, but it isn't smart enough to send it MAC address? Thanks, crzzy1