Become superuser.
On a command line, type the following command.
# ifconfig interface-name group group-name |
Placing the interface in a new group automatically removes it from any existing group.
For example, to remove hme0 from group test and place it in group cs-link, you type the following:
# ifconfig hme0 group cs-link |
This command removes the interface from any existing group and then puts the interface in the group cs-link.