I have 2 domU virtual machines installed on a 11.10 Oneiric Dom0. My internal network is on the 192.168.1 subnet, and when the domU's start, they get ips on the 192.168.122 subnet. I have attempted to follow the instructions here : http://wiki.kartbuilding.net/index.php/Xen_Networking

xend-config.sxp is configured correctly, but neither of my domU's have a config file in /etc/xen to modify. ifconfig reports that I have the following devices :

eth0, lo, tap3.0, vif3.0, vif4.0, virbr0

bridge-utils is installed. I also just attempted to follow these steps :

http://serverfault.com/questions/233201/bringing-the-xenbr0-interface-up-on-xen-under-ubuntu-8-04

sudo brctl addbr xenbr0
sudo brctl addif xenbr0 vif3.0
device vif3.0 is already a member of a bridge; can't enslave it to bridge xenbr0.

Any ideas on next steps are greatly appreciated!