I can ping the PC, but can't connect

Mon, 07/01/2019 - 10:04 By Dave Brooks

Q: I can ping the PC, but can't connect.

A: First, make sure your remote computer can see RPM Remote Print Manager® ("RPM"). Attempt to connect to RPM using the telnet program. Most Unix telnet programs can take an optional port argument. The following command will attempt to connect to the host rpm.somewhere.com on TCP port 515, which is the port RPM listens on for incoming print jobs.

  telnet rpm.somewhere.com 515

If you can connect to RPM, you will probably see the following text (or equivalent).

  Trying rpm.somewhere.com...
  Connected to rpm.somewhere.com
  Escape character is '^]'.

Pressing the Enter key at this point should close the connection and display the following message.

  Socket xxx received unknown command 0xd with arguments  Connection closed by foreign host.

The first part of the above message is RPM's response to an unknown command. Check the RPM log for the same message as it should be logged as a warning. If the message shows up in the RPM log, you have made a successful connection to RPM.

If you get "Connection refused" or "Connection timed out", check and relax port 515 for any firewalls (software or hardware-based) that may be blocking the connection.

If you see a message such as "Unknown host", check your server's DNS configuration (on some machines this is in /ect/hosts) and make sure there is an entry for your PCs hostname, or that your server has the appropriate DNS servers configured.

Open the LPD Options dialog by choosing LPD Options from the Options menu in RPM. If you have turned off "relax the 'port in range' requirement", after initiating the above telnet command, you will see the following message. You will also see it in the RPM log as well.

   Client port xxxx is out of range

Even though these are warnings in the RPM, they merely show that a connection has been made to RPM. You can safely ignore the warnings.