Question

I’m Running a client/server chat messaging deal.

The client program gives me the error message “Host unknown: VCLXXXLR”

On the local network the computer I want to talk to is named “VCLXXXR” but it also has an IP address. However, when I used the IP address it didn’t work either.

The whole system is a simple client-server app ( http://pirate.shu.edu/~wachsmut/Teaching/CSAS2214/Virtual/Lectures/chat-client-server.html ). I appreciate any tips or advice.

Answer 1

The linked code looks ok and the error is very specific. Things you can try:

Verify your code is identical to the listing. Pay special attention to the clients hostname command line argument:

client = new ChatClient(args[0], Integer.parseInt(args[1]));

If you accidentally did:

client = new ChatClient(args[1], Integer.parseInt(args[1]));

That would throw the UknownHostException error that triggers your error message. You can also verify this by changing the following message:

System.out.println("Establishing connection. Please wait ...");

to

System.out.println("Establishing connection to " + serverName + ". Please wait ...");

Then you will know for sure that you are trying to connect to what you think you are.

Failing that, verify that you can ping the hostname or IP address from the command line.