What is two-arm?
The number of ‘arms’ is a descriptive term for how many interfaces are used to connect a device to a network. In two-arm mode, two subnets are used. The VIP is located in one subnet and the load balanced servers are located in the other subnet. The load balancer requires two interfaces. Note that this can be achieved by using two network adapters, or by creating VLANs on a single adapter.