We are currently installing CMS on an Air Force network where restrictions and security are somewhat extreme. We have a network of 70 servers, 2000 ws, and 13 subnets. I was trying to get PXE to work across the nets, and as we had no control on the DHCP services, I was struggling with a solution.
Finally, I was able to convince my network guys to provide a separately configured IP/drop for each of the subnets. I reconstituted an expiring server, upgraded to 2003, added 6 dual NICs.
The only configuration changes were covered in KB article 20695 "Servicing multiple NICs....".
In order to prevent certain thin clients from attempting PXE access, it was necessary to add the MAC exclusions in the PXE configuration utility.
Hope this helps some other newbie that might have a similar situation.