ZyXEL Communications 1000 Manuale Utente

 Chapter 24 Firewall

ZyWALL USG 1000 User’s Guide

• The ordering of your rules is very important as rules are applied in sequence.

Figure 322   Configuration > Firewall       

The following table describes the labels in this screen. 

Table 112   Configuration > Firewall

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.