Firewall Settings (Settings dialog box)
The Use alternate address for firewall connection feature is used to browse for Citrix servers or published applications that are inside a firewall from a client machine that is outside the firewall. The firewall and the Citrix servers must be configured to map the internal network addresses of Citrix servers to external internet addresses. Enter the external address of a Citrix server that is on the subnet to which you want to connect to the Address List.