I installed XEN on Ubuntu 8.04 using this tutorial but after I reboot with the XEN kernel, I don't have xenbr0 device. I see that network-bridge script runs and it creates peth0 device, but not xenbr0.
I have a very basic IP setup, with a single static IP defined in /etc/network/interfaces. The only unusual thing is that my hosting (1&1) gave me a netmask 255.255.255.255, so I had to add the default gateway with this script:
/sbin/route add -host 10.255.255.1 dev eth0 /sbin/route add default gw 10.255.255.1
Everything else is plain vanilla Ubuntu 8.04.