This machine was bound to AD domain. For no apparent reason, it can no longer ping other network segments. The DC and DNS servers are of course on a different segment. It can ping the gateway, but not any next hop. IP address comes from DHCP, which is located on its network segment. All other PCs and Macs on this segment can access all of the network resources. This machine was just rebuilt and is running Snow Leopard 10.6.3 with all of the most recent updates.