Chapter 19 Firewall

Figure 186 Firewall

The following table describes the labels in this screen.

Table 88 Firewall

LABEL

DESCRIPTION

Global Setting

 

 

 

Enable Firewall

Select this check box to activate the firewall. The ZyWALL performs access control

 

when the firewall is activated.

 

 

Allow

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

Asymmetrical

ZyWALL’s LAN IP address, return traffic may not go through the ZyWALL. This is

Route

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. See Section

 

19.5 on page 282 for an example.

 

 

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ZyWALL USG 1000 User’s Guide