Link Load Balancing Example (Dual Legged, HA)

1. The network setup

Figure 1: Link load balancing network configuration (Master/Backup)

The internal network parameters are 10.10.10.0/24, the balancer network parameters 172.17.2.0/24. VRRP advertisements should be sent out on both networks, a separate address space 10.0.0.0/24 is used for that purpose.

The default route of all clients and also of the optional internal router shown on the left is the "network virt" address of the internal network (10.10.10.71 in this example).

The ipforwarding parameter has to be enabled for Link Load Balancing ("set ipforwarding 1").

2. The BalanceNG Master Configuration

The VRRP-Part of the Master configuration uses a priority ov 110 to be able to use VRRP tracking. The complete master configuration is here (conf006a.txt from the Configuration File Collection).

If the link of the Master to the Internal Network fails, the gateway status will change to "down" which in turn would degrade the VRRP priority by 12 from 110 to 98 which would initiate a failover to the backup node immediately.

3. The BalanceNG Backup Configuration

The VRRP-Part of the Backup configuration uses a lower priority of 100. The complete Backup configuration is here (conf006b.txt from the Configuration File Collection).

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