Recent issue I saw, the XenCenter console sees Network 0 but has no IP address. The VM however has an IP when you check. Work around for this, install the Linux guest agent which will allow the VM to pass additional info about itself to your XenServer host.
Mount the image into the guest using:
mount /dev/xvdd /mnt
Then as the root user, execute the install script:
Then reboot the VM and it should work.