User's Manual

Configuring High Availability
Chapter 5: Managing Your Network 87
Note: The DMZ network must not overlap the LAN network.
6. In the DMZ Subnet Mask text box, type the DMZ’s internal network range.
7. To reset the network to its default settings, do the following:
a. Click Default.
A confirmation message appears.
b. Click OK.
The default settings are restored.
8. Click Apply.
A warning message appears.
9. Click OK.
A success message appears.
Configuring High Availability
You can install two Safe@Office 225 appliances on your network, one acting
as the “Master”, the default gateway through which all network traffic is
routed, and one acting as the “Backup”. If the Master fails, the Backup
automatically and transparently takes over all the roles of the Master. This
ensures that your network is consistently protected by a Safe@Office
appliance and connected to the Internet.
The Master and Backup each have separate IP addresses within the local
network. In addition, the Master and Backup share a single virtual IP address,
which is the default gateway address for the local network. The virtual IP
address is used by the Master gateway, which sends periodic signals, or
“heartbeats”, to the network. If the Backup gateway detects that the heartbeat
has stopped (indicating that the Master gateway has failed), it takes over of
the virtual IP address and all of the Master gateway’s roles. When the Master