for wakeonlan you need to set the flag "Wake-on: g" "ethtool -s eth0 wol g" (place it in /etc/rc.local)
When running xen remember that eth0 is renamed to peth0 so "ethtool -s peth0 wol g"
For booting from remote: centos "ether-wake 00:1f:3b:41:c2:05" ubuntu "wakeonlan 00:1f:3b:41:c2:05"
