TCP/IP Stack

Over 75% of Data Server access problems result from improper TCP/IP stack installation and configuration settings. The requirements for Data Server TCP/IP configuration are more stringent than those for simpler programs such as Telnet. Therefore, if Telnet via TCP/IP is working correctly, that does not necessarily indicate that the TCP/IP is configured correctly.

The following are some general suggestions for troubleshooting TCP/IP stack installation and configuration.

  1. Ping the Data Server host using only the host name (obtainable by executing the 'hostname' command on the UNIX computer) to ensure that data is being transferred, as follows:

    ping hostserver

    A successful ping indicates that data is being transferred. The ping results should also resolve the host server's IP address and domain (if applicable). The following is the sample result of a successful ping:

    pinging [] with 32 bytes of data.

  2. If the host server's IP address is not resolved properly, do the following:

    • Check the DNS setup, if a Domain Name Server is used to provide IP lookups. The DNS should be configured to resolve a computer's IP address if given its hostname, and it should also be able to resolve the hostname if given its IP address.

    • Check the local hosts file, usually named hosts, that resides in the Windows directory. The TCP/IP stack that comes with Windows 95 includes a sample hosts file named hosts.sam, located in the windows directory. To utilize the hosts.sam file, add the remote host server's name and IP address to the file with a text editor. It already has some sample definitions to use as a template. Once the host server has been added, rename the file to hosts.

  3. From the UNIX host, ping the workstation to identify the workstation's IP address and hostname. If this is unsuccessful, check the /etc/hosts file or DNS server to verify that the workstation is listed with a valid IP address.

  4. If DNS is being used, from the UNIX host, use the nslookup command on the workstation to display the workstation name and IP address, as follows:

    nslookup workstation_name