Port
Here you can see to which printer port the printout is made (this is configured in the Windows printer). For a network connected printer you will here see the IP address.
When there is a printer port in the Port field you will see a yellow happy symbol 
to the far right on the row. This is an indication that it is possible to print to this MONITOR printer from the computer. If port is missing (if the field is empty), you will instead see a red sad symbol 
. This might indicate that there is no driver for the printer on the computer in question and that it therefore is not possible to print to that MONITOR printer from the computer. Another possible cause is that there might be a driver installed on the computer but that the name has been changed in the Driver / Windows printer field. The name must match the name of the Windows printer.
The red sad symbol is also displayed if a UNC file path is entered in the Driver / Windows printer field, which points to a locally connected (via for example USB) and shared computer in the network. But in that case the red sad symbol does not mean that the printer is not working.