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Figure 102 security > firewall > default rule, Table 42 security > firewall > default rule – ZyXEL Communications NBG410W3G User Manual

Page 174

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Chapter 9 Firewall

NBG410W3G Series User’s Guide

174

Figure 102 SECURITY > FIREWALL > Default Rule

The following table describes the labels in this screen.

Table 42 SECURITY > FIREWALL > Default Rule

LABEL

DESCRIPTION

0-100%

This bar displays the percentage of the ZyXEL Device’s firewall rules storage space

that is currently in use. When the storage space is almost full, you should consider

deleting unnecessary firewall rules before adding more firewall rules.

Enable Firewall

Select this check box to activate the firewall. The ZyXEL Device performs access

control and protects against Denial of Service (DoS) attacks when the firewall is

activated.

Note: When you activate the firewall, all current connections through

the ZyXEL Device are dropped when you apply your changes.

Allow

Asymmetrical

Route

If an alternate gateway on the LAN has an IP address in the same subnet as the

ZyXEL Device’s LAN IP address, return traffic may not go through the ZyXEL

Device. This is called an asymmetrical or “triangle” route. This causes the ZyXEL

Device to reset the connection, as the connection has not been acknowledged.
Select this check box to have the ZyXEL Device 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 ZyXEL Device.
A better solution is to use IP alias to put the ZyXEL Device
and the backup gateway on separate subnets. See

Section

9.6.1 on page 173

for an example.