Using ping to troubleshoot SLIP link problems

Many common problems with all types of SLIP links can be diagnosed with the ping command. ping the remote host:

ping remote_host_IP_address

If ping fails, check the systems at both ends of the SLIP connection to make sure the following are true:

• slattach is running at both ends of the connection.

• The source address of the first machine matches the destination address of the second machine, and the destination address of the first machine matches the source address of the second machine.

• Both ends have the same header compression setting (that is, either both ends expect to send and receive packets with compressed headers, or neither end does).

• Both ends are using the same baud rate.

• The modems on both ends are using the same protocols (does not apply to dedicated links).

If ping is successful when using the IP address of the remote host, you may wish to ping the remote host using the host names by which it should be reachable. Execute the following command:

ping remote_hostname

If ping fails, it may fail with the following message:

   ping: unknown host remote_hostname

• editing the /etc/hosts file on the local host to include an entry for the remote host.

• ensuring that DNS can resolve the remote host name (if DNS is being used).

• ensuring that users use the correct name for the remote host.

If ping is successful, but you are still unable to rlogin or telnet, continue to the next section.