Patent ID: 7945656

Claim:
A method for determining reachability of a device connected to a computer network, the method comprising: receiving at a routing device at least one Internet Control Message Protocol (ICMP) echo request from a requesting device, the at least one ICMP echo request having a destination address associated with a non-echoing device; in response to the received ICMP echo request, sending an address resolution request to the non-echoing device; receiving from the non-echoing device a reply to the sent address resolution request; issuing from the routing device at least one ICMP echo request to the non-echoing device and determining that no response is received to the issued at least one ICMP echo request; receiving at least one subsequent ICMP echo request at the routing device from a requesting device, the at least one subsequent ICMP echo request having a destination address associated with the non-echoing device; in response to the received at least one subsequent ICMP echo request, sending an additional address resolution request to the non-echoing device; receiving from the non-echoing device a reply to the additional address resolution request; and in response to the received reply from the non-echoing device to the additional address resolution request, and absent receipt of any ICMP echo reply from the non-echoing device, sending a proxy ICMP echo reply from the routing device to the requesting device.