Can ISA server be used transparently?

[Frostex]

We've got an interesting problem about to crop up at work, we're moving from an SBS (single server) set up, to an EBS setup which has 4 seperate servers, one of which is the "security server" which as I understand it is just a newer revision of the Microsofts ISA server.

The general idea is that the ISA server sits between the LAN and the gateway, the "normal" set up it seems is to put your router into bridged mode and then set up your public facing IP address on the ISA server. In this configuration the ISA server sort of acts as your router doing the NAT rules and VPN endpoint etc, and the actual router becomes transparent (bridged)

Unfortunately we have a very specialised router (it's actually a PC with bonded ADSL lines) and it cannot function in bridged mode, hence my question, can ISA be set up to be transparent? What sort of experience has anyone had with this kind of set up, good/bad whatever, any input appreciated.

I cant help but think it seems like a redundant thing to do by putting in an internet management server directly behind an internet management server, so maybe losing track of the objective here...

 

[Berg0]

at present (but not for long) we are using ISA for just VPN, we don't use it as our gateway. i don't see a reason why you would be forced to utilize ISA for everything it is capable of?

 

[Frostex]

Well currently our router handles Ipsec VPN tunnels and our SBS server handles client VPN connections.

I think the main reason we required to use it is maintaining a single domain across multiple sites, I think it can apply active directory features across vpn tunnels. But you're right theres no reason to force everything on to the ISA server.