ZyXEL Communications Unified Security Gateway ZyWALL 300, User Manual

Page: 465 / 1156

Chapter 24 Firewall
ZyWALL USG 300 User’s Guide
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• The ordering of your rules is very important as rules are applied in sequence.
Figure 348 Configuration > Firewall
The following table describes the labels in this screen.
Table 122 Configuration > Firewall
LABEL DESCRIPTION
General
Settings
Enable
Firewall
Select this check box to activate the firewall. The ZyWALL performs
access control when the firewall is activated.
Allow
Asymmetrical
Route
If an alternate gateway on the LAN has an IP address in the same subnet
as the ZyWALL’s LAN IP address, return traffic may not go through the
ZyWALL. This is called an asymmetrical or “triangle” route. This causes
the ZyWALL to reset the connection, as the connection has not been
acknowledged.
Select this check box to have the ZyWALL permit the use of asymmetrical
route topology on the network (not reset the connection).
Note: Allowing asymmetrical routes may let traffic from the WAN go
directly to the LAN without passing through the ZyWALL. A
better solution is to use virtual interfaces to put the ZyWALL
and the backup gateway on separate subnets.