• Login to the Setup Wizard
• Navigate to the 'Server Details' tab
• Set 'Interface'='Wan interface'
• Set 'WAN IP Address' (e.g. 80.65.65.65)
• Set 'WAN Netmask' (e.g. 255.255.255.0)
• Set 'WAN Gateway' (e.g. 80.65.65.1)
• Click on 'Save'

NOTE:

• The WAN feature is available on appliance editions only
• You need to have two network interfaces (e.g. 'eth0' and 'eth1')