Hostid.txt file displays "fffffff" as the hostid

Liz Sanderson
Liz Sanderson
  • Updated


Hostid in the hostid.txt file listed as: "ffffffff"

Or you may have received a license already that can not be used by the license server. Open your license file (safe.lic) in a text editor. It may show "ffffffff" as the hostid which is not correct.


The hostid comes from the MAC address of one of your ethernet adapters. On some computers, more than one adapter may be "teamed" or grouped so they function as a single virtual adapter. These teamed adapters may show their ethernet address as "fffffff'

This problem may also be caused when the license server is located on a Virtual Machine with no unique ethernet address or when you have remotely logged into the license server to obtain the hostid.txt file.


You may be able to manually obtain a hostid (MAC or physical address) from your machine.


  1. Open a command prompt. On Windows use Start -> Run -> cmd)
  2. On Windows enter the command ipconfig /all On Linux use the command $ arp
  3. Look for the "Physical Address" of one of your Ethernet Adapters. This should be a 12 digit number separated by dashes.
  4. Copy down the number, remove the dashes and convert all letters to lower case. Keep any leading 0s. This can now be used as your hostid
  5. Send this hostid along with the name of your floating license server computer and your serial number to and we should be able to generate a correct license file.

Officially teamed ethernet adapters are not supported by FlexLM licensing so this step may not work in all situations. You may need to un-team your adapters or add another adapter to generate a useable hostid.

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