If you use proxy authentication and the 'max_user_ip' ACL, this
	directive controls how long Squid remembers the IP addresses
	associated with each user.  Use a small value (e.g., 60 seconds) if
	your users might change addresses quickly, as is the case with
	dialups. You might be safe using a larger value (e.g., 2 hours) in a
	corporate LAN environment with relatively static address assignments.