How do I find out the address of an Icom RP2C DStar Controller?

I have an Icom DStar repeater that I support. While testing, I changed the default IP address of the Icom DStar controller from the default 172.*.*.* address. The question is how to find out what I changed it to? I have a non-routable class C address on my home network (192.168.1.*). I presumed I set it to something in that subnet. I tried nmap to so a ping scan with this command nmap -sP 192.168.1.* but that did not work. Note I did verify the Icom controller DOES respond to a ping.

I used tcpdump to watch the Ethernet NIC and I saw a bunch of arp requests. One of the source IP addresses I then pinged this one and it replied. While the ping was running, I unplugged the network cable from the front of the Icom controller and the ping stopped replying. So, it looked like I confirmed the address. In the RP2C software, I changed the address to the 239 address, entered the password and it worked!

Installing Icom DSTAR Gateway Software

Well, I am starting the process to install the DSTAR gateway software on a server for the W4AFC repeater system. I have read different things about this process. Some have said that I should avoid the Icom software and use ircDD ( I think that’s the name). From what I read, there might be some issues with the installation, but honestly, I have to see for myself if that is an issue of people not being able to follow directions, or an issue with the software. I guess I will give it a try.

I found the directions above on the following website:


D-STAR Gateway Configuration and Operation (from