Different IP addresses for each port of a Portserver TS4

I am trying to pass UDP packets from the serial ports to a host server which will respond to the packet back to the same IP address that it received the packets from in a test set up that is going to mimic a cell connection (don’t want to pay the charges during the testing phase).

While I know that each serial port does appear as its own IP address, when considered as the entire address including the port number, it would be best for my testing and debugging if each serial port had a completely different IP address exclusive of the port number.

Does anyone know if this is possible and how to accomplish it if it can be done.


To assign an IP Address for each port, use the “altip” feature of the PortServer. In this example you will assign an ip address of to port 16 of the PortServer. Type the following 3 commands from the PortServer prompt:

#> set altip ip= group=16

#> set port range=16 group=16

#>boot action=reset

Now the port can be accessed by telneting to

*Note the IP address must be on the same network segment as the Ethernet interface of the PortServer

I guess I was unclear. The individual address needs to be two way, i.e. send to and sending from. The set altip command only sets the IP in one direction, to the port not from the port. I have since found out that what I want to do is not possible with the terminal server.

What you are trying to do could be achieved by putting a router inline. Perhaps not the most cost effective solution but a Digi TransPort WR21 would achieve what you are trying to do through its firewall rules.

Nicholas, Thanks. I had thought of that as I also have a WR21 and you are correct it will work.