3Com 3C16111 - SuperStack 3 Firewall Web Site Filter, Руководство пользователя

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144 C
HAPTER
10: C
ONFIGURING
H
IGH
A
VAILABILITY
The primary and backup Firewalls use a “heartbeat” signal to
communicate with one another. This heartbeat is sent between the
Firewalls over the network segment connected to the LAN ports of the
two Firewalls. The interruption of this heartbeat signal triggers the
backup Firewall to take over operation from the active unit of the High
Availability pair. The time required for the backup Firewall to take over
from the active unit depends on the Heartbeat Interval and the Failover
Trigger Level.
4 Enter the Heartbeat Interval time in seconds. This interval is the amount
of time in seconds that elapses between heartbeats passed between the
two Firewalls in the High Availability pair.
5 Enter the Failover Trigger Level in terms of the number of missed
heartbeats. When the backup unit detects this number of consecutive
missed heartbeats, the backup Firewall will take over operation from the
active unit.
If, for example, the Heartbeat Interval and the Failover Trigger Level are 5
seconds and 2 missed heartbeats respectively, the backup Firewall will
take over from the primary Firewall after 10 seconds in the event of a
failure in the primary Firewall.
6 Click the Update button. Once the Firewall has been updated, a message
confirming the update will be displayed at the bottom of the browser
window. If you have modified the
Enable High Availability setting, you
will need to restart the Firewall for change to take effect.
Configuring High
Availability on the
Backup Firewall
The backup Firewall should not be configured through the Web interface.
Instead, configure the backup Firewall by exporting the preferences file
from the primary unit and importing the file into the backup unit. This
method assures uniform configuration of the two Firewalls in the High
Availability pair. To do this:
1 Log into the primary Firewall. Click the Tools button on the left side of the
browser window and then click the Configuration tab at the top of the
window. Next, click the Export button.
2 Choose a location to save the primary Firewall’s preferences file. This file
is named “3Com_firewall.exp” by default, but can be renamed. The
export process may take up to one minute.
3 Log out of the primary Firewall.
DUA1611-0AAA02.book Page 144 Thursday, August 2, 2001 4:01 PM