Adding a connection to the heartbeat interface

Note: The primary and failover unit systems are connected via their heartbeat interfaces on a private network. It's critically important that this network isn't congested and suffers as little latency as possible. For these reasons, we recommend that you use a crossover cable for this connection. Using a crossover cable also minimizes the risk of failure because the switch the heartbeat interface is on could fail.


  • Set up a private network consisting of only two Smoothwalls connected via their heartbeat interfaces by using a crossover cable.
  • If you're not using Smoothwall Filter and Firewall hardware appliances, the primary and failover units should both use the same types of hard disk drives, RAM, and must be the same type and number of network interface cards.
  • The failover unit must be plugged into all the switches that the primary system is plugged into.
  • SSH must be turned on in the primary system, see our help topic,Allowing a remote connection to the Smoothwall Filter and Firewall.
  • Adding new Smoothwall access rules.


  1. In the primary Smoothwall, on the NETWORK menu, under the Configuration submenu, click Interfaces.
  2. Locate the interface to be used by the hardware failover master and failover unit systems to communicate with each other, place your mouse cursor over it and click Edit.
  3. In the Edit interface dialog box, enter a meaningful Name for this interface.
  4. From the Use as list, select the Heartbeat interface option.
  5. If MAC spoofing is used, enter the new Spoof MAC address.
  6. Optionally, enter the maximum transmission unit (MTU) value needed in your environment.
  7. Click Save changes.

Follow-up task