You cant. From: isalist-bounce@xxxxxxxxxxxxx [mailto:isalist-bounce@xxxxxxxxxxxxx] On Behalf Of Vineet Tripathi Sent: Wednesday, March 04, 2009 8:26 AM To: ISA Mailing List Subject: [isalist] Two external interface on isa I want to setup ISA Server with 3 network cards. One will be connected to the internal network, where all client workstations and corporate file/mail servers are. Two other network cards will be connected to two independent external networks; each external network has it's own connection to the Internet (to different ISP). . I want ISA server to route packets between those two external networks. How I can do this?