Configuring outbound Multi-Link settings

Outbound Multi-Link elements combine NetLinks and set options for the high availability and load balancing features.

You must configure the basic settings for the Round Trip Time or Ratio methods in the properties of each NetLink.

To monitor the status of the NetLinks, the firewall must be configured to probe each NetLink. Probing is always recommended, and it is mandatory with the following features:

  • The Ratio-based load-balancing method
  • Failover to Standby NetLinks
  • Inbound traffic balancing with dynamic DNS updates

The probe is made using ICMP echo requests (ping) to IP addresses you define. Make sure the Probe IP Addresses that you select produce a reliable measurement of the link performance. For example, probing the IP address of an ADSL router usually succeeds even if the ISP network is unreachable. Probing the default gateway provided to you by the ISP might succeed even if the ISP is not able to forward traffic anywhere outside the ISP’s own network. Several alternative probe IP addresses can be added to avoid probing failures caused by a probed host going down.