You use the ifconfig command to configure groups. This command uses a new group parameter that requires a group name. The ifconfig command places both the IPv4 and IPv6 instances of the interface in that group. The group parameter has the following syntax:
ifconfig interface-name group group-name
Avoid using spaces in group names. The ifconfig status display does not show spaces. Consequently, do not create two similar group names. If one of the group names contains a space, these group names look the same in the status display. However, the group names are different. This difference might be confusing.
Placing the IPv4 instance under a particular group automatically places the IPv6 instance under the same group. Also, you can place a second interface, which is connected to the same subnet, in the same group by using the same command. See How to Configure a Multipathing Interface Group With Two Interfaces.
You can remove an interface from a multipathing group by using a null string with the group sub-command. See How to Remove an Interface From a Group.
You can place an interface in a new group when the interface is already part of some multipathing group. You do not need to remove the interface from any existing group. By placing the interface in a new group, the interface is automatically removed from any existing group. See How to Move an Interface From an Existing Group to a Different Group.
You can have any number of network adapters that you can configure in the same multipathing group. You cannot use the group parameter with logical interfaces. For example, you can use the parameter with hme0, but not with hme0:1.
You must connect all the interfaces in the multipathing group to the same IP link. When an interface fails, the failover operation moves all the IP addresses from the interface that has failed to a functional interface in the group. The functional interface must be connected to the same IP link. Consequently, routers can continue to rout packets to the addresses that have been switched to the functional interface.