User's Manual Part 1

Configuring High Availability
Chapter 5: Managing Your Network 123
• You must have at least two identical Safe@Office appliances.
• The appliances must have identical firmware versions and firewall rules.
• The appliances' internal networks must be the same.
• The appliances must have different real internal IP addresses, but share the
same virtual IP address.
• The appliances' synchronization interface ports must be connected either
directly, or via a hub or a switch. For example, if the DMZ is the
synchronization interface, then the DMZ/WAN2 ports on the appliances
must be connected to each other.
The synchronization interface need not be dedicated for synchronization only. It
may be shared with an active internal network.
You can configure HA for any internal network, except the OfficeMode network.
Note: You can enable the DHCP server in all Safe@Office appliances. A Passive
Gateway’s DHCP server will start answering DHCP requests only if the Active
Gateway fails.
Note: If you configure HA for the WLAN network:
• A passive appliance's wireless transmitter will be disabled until the
gateway becomes active.
• The two WLAN networks can share the same SSID and wireless
frequency.
• The WLAN interface cannot serve as the synchronization interface.