In my last place in the main HQ was all one large network (set-up that way when I joined) and I set the server up on the same network, it was mainly used for desktop deployment. It was handy as I could image/re-image a machine anywhere in the building, I never tried to go across our site to site links as they were too slow.
In my new place I've got in on the servers VLAN but getting it across another VLAN is as simple as adding the options to the DHCP scope and obviously ensuring the there's inter VLAN routing.
I had considered setting up a portable FOG server on a laptop for imaging in some of our remote sites but never got around to it.
FOG does support multicast for bulk deployment, it works very well but it can saturate some networks, I've used it recently but all the PC's were connected into the same switch as the server just to ensure it didn't cause any issues.
edit:
I've used FOGs built-in DHCP on VMs in the past and it works fine. On corporate networks, I've always used Windows Server DHCP and added the appropriate options.
In my new place I've got in on the servers VLAN but getting it across another VLAN is as simple as adding the options to the DHCP scope and obviously ensuring the there's inter VLAN routing.
I had considered setting up a portable FOG server on a laptop for imaging in some of our remote sites but never got around to it.
FOG does support multicast for bulk deployment, it works very well but it can saturate some networks, I've used it recently but all the PC's were connected into the same switch as the server just to ensure it didn't cause any issues.
edit:
I've used FOGs built-in DHCP on VMs in the past and it works fine. On corporate networks, I've always used Windows Server DHCP and added the appropriate options.