Is this a flakey set up ??? cisco 1600 router 4 locations tunnel using gre at the routers --------->router------>clients routers are doing DCHP ethernet side is bound to public's and private. Computers at location B logon to DC @ location A through the GRE tunnel Here's my question the GRE tunnel between all 4 locations make up a DMZ?? Is it possible to and isn't more secure to have something like this router------>----isa with 3 nic's--------->internal network Can I pass login credentials through the ISA over the DMZ to the DC or setup a DC and pass AD replication over the DMZ seems like a more secure setup. Please help me out a little here Jim