ZyXEL Communications Prestige 662H Series User Manual page 179

Prestige 662H/HW Series User's Guide
Table 50 Firewall: Threshold (continued)
LABEL
One Minute High
Maximum
Incomplete Low
Maximum
Incomplete High
TCP Maximum
Incomplete
Action taken when
the TCP Maximum
Incomplete
threshold is
reached.
Delete the oldest
half open session
when new
connection
request comes
Deny new
connection
request for
Back
Apply
Cancel
179
DESCRIPTION
This is the rate of new half-open sessions that
causes the firewall to start deleting half-open
sessions. When the rate of new connection
attempts rises above this number, the
Prestige deletes half-open sessions as
required to accommodate new connection
attempts.
This is the number of existing half-open
sessions that causes the firewall to stop
deleting half-open sessions. The Prestige
continues to delete half-open requests as
necessary, until the number of existing half-
open sessions drops below this number.
This is the number of existing half-open
sessions that causes the firewall to start
deleting half-open sessions. When the
number of existing half-open sessions rises
above this number, the Prestige deletes half-
open sessions as required to accommodate
new connection requests. Do not set
Maximum Incomplete High to lower than the
current Maximum Incomplete Low number.
This is the number of existing half-open TCP
sessions with the same destination host IP
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.
Select this radio button to clear the oldest half
open session when a new connection request
comes.
Select this radio button and specify for how
long the Prestige should block new
connection requests when TCP Maximum
Incomplete is reached.
Enter the length of blocking time in minutes
(between 1 and 256).
Click Back to return to the previous screen.
Click Apply to save your changes back to the Prestige.
Click Cancel to begin configuring this screen afresh.
DEFAULT VALUES
100 half-open sessions per minute.
The above numbers cause the
Prestige to start deleting half-open
sessions when more than 100
session establishment attempts
have been detected in the last
minute, and to stop deleting half-
open sessions when fewer than 80
session establishment attempts
have been detected in the last
minute.
80 existing half-open sessions.
100 existing half-open sessions.
The above values causes the
Prestige to start deleting half-open
sessions when the number of
existing half-open sessions rises
above 100, and to stop deleting
half-open sessions with the
number of existing half-open
sessions drops below 80.
30 existing half-open TCP
sessions.
Chapter 14 Firewall Configuration