ZyXEL Communications P-660HN-F1 9.3The Firewall Rule Screen

Chapter 9 Firewalls

The following table describes the labels in this screen.

Table 52 Security > Firewall > General

LABEL	DESCRIPTION
Active 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.
Bypass Triangle	If an alternate gateway on the LAN has an IP address in the same subnet as the
Route	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 9.5.4.1 on page 169 for an example.
Packet Direction	This is the direction of travel of packets (LAN to LAN / Router, LAN to WAN,
	WAN to WAN / Router, WAN to LAN).
	Firewall rules are grouped based on the direction of travel of packets to which they
	apply. For example, LAN to LAN / Router means packets traveling from a
	computer/subnet on the LAN to either another computer/subnet on the LAN
	interface of the ZyXEL Device or the ZyXEL Device itself.
Default Action	Use the drop-down list boxes to select the default action that the firewall is to take
	on packets that are traveling in the selected direction and do not match any of the
	firewall rules.
	Select Drop to silently discard the packets without sending a TCP reset packet or
	an ICMP destination-unreachable message to the sender.
	Select Reject to deny the packets and send a TCP reset packet (for a TCP
	packet) or an ICMP destination-unreachable message (for a UDP packet) to the
	sender.
	Select Permit to allow the passage of the packets.
Log	Select the check box to create a log (when the above action is taken) for packets
	that are traveling in the selected direction and do not match any of your
	customized rules.
Expand...	Click this to display more information.
Basic...	Click this to display less information.
Apply	Click this to save your changes.
Cancel	Click this to restore your previously saved settings.

9.3The Firewall Rule Screen

"The ordering of your rules is very important as rules are applied in turn.

Refer to Section 9.5 on page 166 for more information.

	157
P-660HN-F1 User’s Guide