Gateway to gateway VPN SBS ISA firewall

[heals1ic]

I intend to setup a gateway to gateway VPN using 2 DG834G ADSL routers to connect a remote and local site. The local site currently has a windows SBS 2003 server with ISA installed as the firewall for the internal network and the remote site is just a bunch of clients.


localclients --> ISA Firewall -->gatewayA --> internet --> gatewayB --> remoteclients

local clients have subnet 192.168.10.0 and remote clients have subnet 192.168.1.0

How do I allow local traffic from both sites through the ISA firewall while still protecting external traffic?

In this scenario is the ISA firewall needed at all?

Should I unstall it and rely on the gateway firewall?

It is such a comprehensive firewall and it would be a shame to uninstall if that is the case.

Any suggestions?

 

[heals1ic]

Should I setup the gateway on the local side to pass traffic through to the ISA firewall like a DMZ but how do I setup ISA to allow a whole subnet access?

Do I then implement a firewall policy or a firewall filter or a static route in the routing and remote access server? Or maybe something else??