f6a461ee_IPsec_VPN___UntangleWiki__Description
[Name] External IP [Description] 
Use this field to configure the IP address that is associated with the IPsec VPN on the Untangle server. Normally this field will be read-only and will automatically be populated based on the Interface selected above. If you select Custom as the interface, you can then manually enter the local IP address.
IPsec VPN - UntangleWiki
Description