Client/Server Mismatch

This section is applicable to installations involving a license file activation type. This licensing method is gradually being replaced by the user credentials activation type starting with Thermo‑Calc 2025a.

For some network installations there can be a naming mismatch that causes errors. The server (where the license management software is installed) gets information from its DNS servers that an IP address (aaa.bbb.ccc) belongs to a computer (Computer A). But the client computer identifies itself as having a different IP address (aaa.bbb.ccc.eee) for the same computer (Computer A).

Even if the IP address of the client computer belongs to a subnet range listed in the license file, there is a problem with accessing the license file because the computer name does not match the information.

You may need your organisation’s network administrator to assist with this issue.

Step 1. Compare computer names on the client computer and server

  1. On the client computer, start a command prompt cmd.exe and type ipconfig /all. Press Enter. A variety of data is displayed on screen. Write down the following information for later comparison:
    • Hostname
    • DNS Suffix
    • Current IPv 4 Address
  2. In the command window, type nslookup <client_computer_name>, where client_computer_name is the actual name of the client. Press Enter.

    This shows what information is saved on the DNS Servers used by the client computer. This information should match what is shown in the output from the first step.

  3. On the server that holds the license management software, open a command prompt and run the command line: nslookup client_computer_name. The output lists the information for this server.

    Does it match the information given by the command ipconfig /all on the client computer? If not try the following.

Step 2. Try these options to correct the issue

  1. If the client computer has a dynamic (DHCP) IP address, either change it to a static one or make a reservation on the DHCP Server so that the computer always get the same IP address.
  2. Update the records on the DNS Servers used by both the client computer and the server computer.

You can also configure the computer names and IP addresses in the local Hostfile of the client and server:

  1. On the client computer, make a backup copy of the file C:\Windows\System32\drivers\etc\hosts.
  2. Open the original in a simple text editor.
  3. Add a new line which contains the IP and name of the server, for example: 192.168.29.27 license_server.thermocalc.se.
  4. Save the changes.
  5. On the server, make a backup copy of the file /etc/hosts.
  6. Open the original in a simple text editor.
  7. Add a new line which contains the IP and name of the client, for example: 192.168.29.47 Computer_A.thermocalc.se.
  8. Save the changes.
  9. In the host file, there is an example of how the operating system (Windows or Linux) wants the line in the hosts file to look like.