Tips for finding Knowledge Articles

  • - Enter just a few key words related to your question or problem
  • - Add Key words to refine your search as necessary
  • - Do not use punctuation
  • - Search is not case sensitive
  • - Avoid non-descriptive filler words like "how", "the", "what", etc.
  • - If you do not find what you are looking for the first time,reduce the number of key words you enter and try searching again.
  • - Minimum supported Internet Explorer version is IE9
Home  >

KB-0880: Why does adjoin hang trying to set the machine password?

Mac & PC Management Service ,  

12 April,16 at 10:57 AM

Applies to: Centrify DirectControl 4.0 to 4.1.1


Why does adjoin hang trying to set the machine password?


In DirectControl 2.x, machine password changes require UDP port 464.

In DirectControl 3.x, the Kerberos libraries (version 1.4.1) only support machine password changes over TCP port 464. This restriction was made because we were getting failures when very large PACs (big group memberships) were being passed over UDP.

In DirectControl 4.0 and 4.1.0, we adopted a patch by Todd Stretcher to Kerberos libraries version 1.4.3 that first tries a machine password change over UDP, just like the rest of the Kerberos protocol exchanges, and if a response too big error comes back it fails over to TCP. For this reason, the UDP port 464 should be open.


With DirectControl 4.0 or 4.1.0, both UDP port 464 and TCP port 464 should be opened on the firewall to allow Kerberos-based authentication.


Fixed in DirectControl 4.1.2. In this version, by default, we configure Kerberos to use only TCP for all Kerberos-related protocols to avoid issues with MTU path discovery causing fragmented UDP packets, and routers that are configured to silently drop UDP packets beyond configured size thresholds.  This option will be configurable for users who wish to revert to the UDP with TCP fail-over behavior.

Still have questions? Click here to log a technical support case, or collaborate with your peers in Centrify's Online Community.