ZyXEL Communications P-661HW manual 178

P-661H/HW Series User’s Guide

Table 67 Firewall: Threshold (continued)

LABEL	DESCRIPTION	DEFAULT VALUES
Maximum	This is the number of existing half-open	80 existing half-open sessions.
Incomplete Low	sessions that causes the firewall to stop
	deleting half-open sessions. The ZyXEL
	Device continues to delete half-open requests
	as necessary, until the number of existing
	half-open sessions drops below this number.
Maximum	This is the number of existing half-open	100 existing half-open sessions.
Incomplete High	sessions that causes the firewall to start	The above values causes the
	deleting half-open sessions. When the	ZyXEL Device to start deleting half-
	number of existing half-open sessions rises	open sessions when the number of
	above this number, the ZyXEL Device deletes	existing half-open sessions rises
	half-open sessions as required to	above 100, and to stop deleting
	accommodate new connection requests. Do	half-open sessions with the
	not set Maximum Incomplete High to lower	number of existing half-open
	than the current Maximum Incomplete Low	sessions drops below 80.
	number.
TCP Maximum	This is the number of existing half-open TCP	30 existing half-open TCP
Incomplete	sessions with the same destination host IP	sessions.
	address that causes the firewall to start
	dropping half-open sessions to that same
	destination host IP address. Enter a number
	between 1 and 256. As a general rule, you
	should choose a smaller number for a smaller
	network, a slower system or limited
	bandwidth.
Action taken when the TCP Maximum Incomplete threshold is reached.
Delete the oldest	Select this radio button to clear the oldest half
half open session	open session when a new connection request
when new	comes.
connection
request comes
Deny new	Select this radio button and specify for how
connection	long the ZyXEL Device should block new
request for	connection requests when TCP Maximum
	Incomplete is reached.
	Enter the length of blocking time in minutes
	(between 1 and 256).
Apply	Click Apply to save your changes back to the ZyXEL Device.
Cancel	Click Cancel to begin configuring this screen afresh.

178 Chapter 9 Firewall Configuration