In the console tree of ISA Server Management, click
General.
In the details pane, click Define IP Preferences.
On the IP Routing tab, select Enable IP
routing.
Notes
To open ISA Server Management, click Start, point to
All Programs, point to Microsoft ISA Server, and then
click ISA Server Management.
For ISA Server 2006 Enterprise Edition, expand
Microsoft Internet Security and Acceleration
Server 2006, expand Arrays, expand
Array_Name, expand Configuration, and then
click General.
For ISA Server 2006 Standard Edition, expand Microsoft
Internet Security and Acceleration Server 2006, expand
Server_Name, expand Configuration, and then
click General.
Important
Although IP routing improves performance, disabling IP routing
is considered more secure. When IP routing is disabled, ISA Server
sends only the data (and not the entire packet) to the
destination.