Setting up xen with nat and dhcp in debian lenny (5.0)

Information on setting xen with NAT in debian lenny is scattered over the internet. One resource mention about patching some files.

This guide is for people who want to do the setup with the most minimal change to debian default setup.

1. In /etc/xen/xen-config.sxp, comment (put # in front of) the "(network-script network-dummy)" and "(vif-script vif-bridge)". Comment out (erase # in front of) the "(network-script network-nat)" and "(vif-script vif-nat)".
2. Put "brctl addbr $2" after the line saying "echo $*". Then put "ifconfig $2 xxx.xxx.xxx.xxx" at the end of the file, where xxx.xxx.xxx.xxx is a local static IP address.
3. Set up your dhcp server accordingly by have it listen to the interface, the default is xenbr0. The ip of xenbr0 will be automatically set to xxx.xxx.xxx.xxx from step 2 above. Restart your dhcp server if necessary.
4. Run your xen image.
5. Then restart ipmasq by running /etc/init.d/ipmasq restart .
6. Profit!

This should be clear for people who know enough to install xen. Leave a comment if you want to ask question. And please leave a comment if you know a better neat way to configure default xen's lenny installation. The above is really a hack with the least amount of modification I can think of.