One problem you may encounter is that your Dom0 (or any other DomU connected to the bridge on eth0) has problems with internet access after getting your Firewall running in the DomU.
This probably is the NIC causing the problem, you can check the by doing 'tcpdump -nvvi eth0' in your Dom0 and then initiating some traffic, you can run a 'traceroute microsoft.com' and see what output tcpdump gives, if there's any error about 'bad chksum' then you need to modify your NIC driver. The problem is caused by checksum offloading in the NIC driver and you can check it with the following commands:
Code:
ethtool -k eth0 -- display driver setting, you should see something like this:
tx-checksumming: on If that's the case, disable it with:
Code:
ethtool -K eth0 tx off
You'll probably need to disable it in all the DomUs you have running.
See if that's your problem.
[/edit]Why do you have the Linksys and Shorewall running? You don't need both as one firewall will do and two may cause you problems.