Intel 1520 manual Following table shows the options

The following table shows the options:

Option	Description
Options to Verify freshness	Choosing this option lets you configure how
	the appliance asks the original content server
	to verify the freshness of objects (revalidate
	them) before serving them.
	Select from one of the following options and
	press Enter. After pressing Enter press
	CTRL-X to save your changes and return to
	the previous screen.
	❚ When The Object Has Expired—The
	appliance revalidates objects with explicit
	expiration dates after they expire.
	Otherwise, it uses heuristic methods to
	evaluate freshness and revalidates the
	object should it be stale.
	❚ When The Object Has Expired Or Has No
	Expiry Date—The appliance revalidates
	objects with explicit expiration dates after
	they expire. All other documents are
	revalidated before serving.
	❚ Always—The appliance always revalidates
	objects before serving them.
	❚ Never—The appliance never checks object
	freshness.
Freshness information	Specifies the minimum freshness information
	required when considering to cache a
	document.

Select from one of the following options and press Enter. After pressing Enter press CTRL-X to save your changes and return to the previous screen.

❚An Explicit Lifetime—The appliance only caches objects with Expires headers or

Cache-Control: max-age headers.

❚A Last Modified Time—The appliance only caches objects with Expires headers, or

Cache-Control: max-age headers, or Last-Modified headers.

❚Nothing—The appliance caches documents regardless of freshness headers.

78Intel NetStructure Cache Appliance Administrator’s Guide