If you are connected to the Inter/Intranet (the little box to the left of the button Refresh IP is green) you can activate IPchat (note that you must also check the appropriate box in Setup|IPchat and enter some information there). IPchat will then scan all the IP address ranges that you have defined in the IPDB file (the default file name is IPDB.txt). You can edit this file with a simple text editor like NotePad. The scanning process is repeated in regular user-defined intervals. A list of people who use IPchat on a regular basis is available here.

As soon as DynamIP finds another IPchat client at one of the scanned IP addresses it will add some information about that other client (handle, time found, IP address) to the Chatlist (each line of the Chatlist contains information about 1 chat participant). You will realize that your machine gets added to the Chatlist as well; if your own machine doesn't show up on your Chatlist then there is something wrong [could it be that you entered a static IP address that is not correct?].

Assuming that IPchat is running fine you can chat with everybody on your Chatlist similar to IRC; whatever you type into the chat input window at the very bottom of the DynamIP window gets sent to everybody else as soon as you hit the Enter key. For actions targeted at individual chat participants (e.g. Hail) you must first select the chat participant (click on the appropriate line in the Chatlist to select it).

IPchat uses port #1499 by default. If you need to change this setting - for whatever reason - you'll find the instructions here. More detailed and technical information about IPchat and the chat engine is available  here.