I consider myself fairly avid with Ubuntu and Linux, but this one has me stumped. I built up a Xen Server using Ubuntu 12.04 as the base operating system. It has multiple domUs running on it. My home network has a statically defined network where I got all the network connectivity going peachy. The server was moved to a permanent home this morning. So, the network configuration on the main system had to change. Again, another static network, but now I can't ping the upstream gateway from the host. As the VMs use this NIC over a bridge, they too are broken. Ping responds with "destination host unreachable." I simplified the networking down to a simple static network as seen below (no bridge or anything) just to get it to work. Here's the contents of my /etc/network/interfaces file: auto lo iface lo inet loopback auto eth0 iface eth0 inet static address 216.7.188.228 gateway 216.7.188.225 netmask 255.255.255.240 broadcast 216.7.188.255 network 216.7.188.0 dns-nameservers 8.8.8.8 8.8.4.4 Here's the contents of route -n 0.0.0.0 216.7.188.225 0.0.0.0 UG 100 0 0 eth0 216.7.188.224 0.0.0.0 255.255.255.240 U 0 0 0 eth0 And the results of pinging the gateway: PING 216.7.188.225 (216.7.188.225) 56(84) bytes of data. From 216.7.188.228 icmp_seq=1 Destination Host Unreachable From 216.7.188.228 icmp_seq=1 Destination Host Unreachable From 216.7.188.228 icmp_seq=1 Destination Host Unreachable Again, this worked in one network flawlessly (obviously with different parameters in the interfaces file). I did try using eth1 (as there are two NICS on the server (in case the MAC address got flipped on bootup). No success there. Yes, the cable is in the right port now :) Any thoughts? I appreciate the help!