When I open the Infront Professional Terminal, I receive the following message: “Attempting to connect to another server..” What do I do?

Your firewall is blocking the access to the Infront Professional Terminal. In order for the Infront Professional Terminal to work properly, you have to make sure that all the ports and IP addresses are open.

The following IP addresses and ports are in use by the Infront Professional Terminal and need to be opened in customer firewalls.

Follow instructions below:

  • Click OK on the Error message
  • Click on the three dots to the upper right corner of the desktop
  • Click on Settings → Open Advanced Settings
  • Change to any of the ports below.
  • Click OK and restart the Infront Professional Terminal.

Ports and protocols


IP Addresses Used by Infront

The below outlined IP address ranges and ports are in use by Infront software, and needs to be opened in the client’s firewall settings. Please note that only one of the outlined ports below need to be opened in the firewall settings, not all of them. For this to work, you would need firstly to white-list *.infrontservices.com (* = all).
Go thereafter to settings then open advanced settings:

  1. Under the Login Server section, tick off the Use DNS names, press OK, exit and restart.
  2. If this does not work, set Web sockets to force, press OK, exit and restart.
  3. If this does not work, set Web sockets to force (secured), press OK, exit and restart.


The reason to having several IP addresses, is because we believe that we should have as many as possible inter-chained links between the client and the source. Adding thus a so-called load-balancer on top of the server environment will add another link in the chain, consequently making it less secure. Infront’s environment is currently running on several locations, whereby the switchover mechanism is built into the client.

Additional connectivity options are available. Please contact support if the above does not work.