In the console tree of ISA Server Management, click
Cache.
In the details pane, click the Cache Rules tab, and then
select the applicable cache rule.
On the Tasks tab, click Edit Selected Rule.
On the HTTP tab, select the Enable HTTP caching
check box.
To specify how long HTTP objects will remain in the cache,
expressed as a percentage of the time of the content's existence,
type a number in Set TTL of objects.
To specify how long HTTP objects will remain in the cache,
expressed as a time, type the minimum and maximum time in No
less than and No more than.
To retain objects beyond their expiration time in the cache,
but in accordance with the settings you configured, select Also
apply these TTL boundaries to sources that specify
expiration.
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 Cache.
For ISA Server 2006 Standard Edition, expand Microsoft
Internet Security and Acceleration Server 2006, expand
Server_Name, expand Configuration, and then
click Cache.
Important
The higher the percentage you specify in Set TTL of
objects, the less frequently the cache is updated.
When you shorten the Time to Live (TTL) by specifying the
Also apply these TTL boundaries to sources that specify
expiration option, objects in the cache will be more recent.
However, there may be some degradation in network performance,
because objects are retrieved frequently from the Internet.
To restore the TTL defaults, click Restore
Defaults.
Even when you disable HTTP caching for all cache rules, ISA
Server allocates cache memory. To stop ISA Server from allocating
memory, set the cache size to 0.