Failover

Goal

To use the 6310-DX's cellular modem as a backup WAN connection for the primary WAN Ethernet port.  The 6310-DX will use the WAN Ethernet port as its main Internet connection, and will fail over to the cellular modem if the primary connection goes down.

Setup

This article assumes the LAN ports are operating under default settings, which provide DHCP connectivity to devices connected to the 6310-DX's LAN ports.  For more details on the default settings of the 6310-DX, see the Default Settings section of the 6310-DX User's Manual.

For this setup, you will need the 6310-DX with both a primary WAN Ethernet connection, and a cellular modem connection.

Sample

The sample configuration below shows a 6310-DX with two internet connections.  The WAN Ethernet interface will be used as the primary Internet connection.  The 6310-DX is setup to test the WAN Ethernet connection twice every minute.  If three sequential tests fail, then the 6310-DX will restart the WAN Ethernet connection, and failover to the cellular modem's Internet connection until the WAN Ethernet connection is re-established.

Summed up, if a 6310-DX's primary WAN connection fails, with the below configuration the 6310-DX will failover to the cellular modem in under 2 minutes.

Sample Configuration

Open the configuration profile for the 6310-DX and make the following changes.

In the Modem -> Metric entry, ensure the value is set to a number higher than the the value in Network -> Interfaces -> WAN -> IPv4 -> Metric.  The interface with the lower metric takes higher precedence.  By default, the cellular modem metric should be 3 and the WAN Ethernet's metric should be 1, making WAN Ethernet the primary and the cellular modem the backup Internet connection.

Next, open the Network -> Interfaces -> WAN -> IPv4 -> Active Recovery section and make the following changes. 

  • Enabled:  checked
  • Restart interface:  checked
  • Interval:  30s
  • Attempts:  3
  • Test targets:  a ping test to 128.136.167.120 and a HTTP test to firmware.accns.com
    Note: 2 different tests are recommended to prevent false positives

NOTE: Best practices dictate that redundant tests (with divergent failure conditions) will be the best way to ensure proper connectivity monitoring/active recovery. With only a single test type, false positives could be reported.