Chapter 11 Firewall
Figure 135 SECURITY > FIREWALL > Default Rule (Router Mode)
The following table describes the labels in this screen.
Table 48 SECURITY > FIREWALL > Default Rule (Router Mode)
LABEL | DESCRIPTION |
This bar displays the percentage of the ZyWALL’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. |
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Enable Firewall | Select this check box to activate the firewall. The ZyWALL 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 ZyWALL are dropped when you apply your changes. |
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|
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 IP alias to put the ZyWALL and the |
| backup gateway on separate subnets. See Section 11.6.1 on |
| page 202 for an example. |
| 203 |
ZyWALL 2 Plus User’s Guide | |
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