Sometimes a problem with ARP occurs after you reinstall your OS, due to an old, cached ARP entry on InterNAP's end. If you're running some version of Linux, give it a good, swift kick with these commands, entered onto the command line via your VNC console:
ping w.x.y.252 -I w.x.y.z
ping w.x.y.253 -I w.x.y.z
ping w.x.y.254 -I w.x.y.z
Where w.x.y.z is the IP address on your VDS that isn't responding properly.