User`s guide

Chapter 9 Firewall Screens
LAN-Cell 2 User’s Guide
185
Figure 102 SECURITY > FIREWALL > Default Rule
The following table describes the labels in this screen.
Table 69 SECURITY > FIREWALL > Default Rule
LABEL DESCRIPTION
0-100% This bar displays the percentage of the LAN-Cell’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 LAN-Cell 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 LAN-Cell 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
LAN-Cell’s LAN IP address, return traffic may not go through the LAN-Cell. This is
called an asymmetrical or “triangle” route. This causes the LAN-Cell to reset the
connection, as the connection has not been acknowledged.
Select this check box to have the LAN-Cell 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 LAN-Cell. A
better solution is to use IP alias to put the LAN-Cell and the
backup gateway on separate subnets. See Asymmetrical
Routes and IP Alias on page 206 for an example.