How to assign the IP address to the BigIP system Interface ?

Steve, to find which ip address assigned to the interface you must find:

1. Vlan assigned to that interface in you case 1.7 -> go to Network / Vlans.
2. Go to Self IPs and find which ip address assigned to the Vlan.

To assign ip address to the interface:

1. Go to Network / Vlan and create a new one and assign to the interface for example 1.7.
2. Go to Network /Self IPs and create ip address and assign it to the new vlan.