Trunk cannot be activated due to Invalid External Port address

Users who upgraded their UAG server to Update 1 may receive an error upon activation “Error: Trunk <Trunk name> cannot be activated due to the following: Invalid External Port address. Please choose a different port.”

This situation may happen if you are running a UAG array, and the array has a redirect trunk (from HTTP to HTTPS) configured. With Update 1, UAG now allows the user to select any external port on a trunk, but this functionality has not been fully enabled for a redirect trunk in Array mode and this may lead to this error being shown.

If you run into this situation, please open a support case with Microsoft CSS, and a support engineer will help you deal with the situation.

Comments (10)

  1. Anonymous says:

    Hi Ben

    In addition to the above mentioned situation, we experienced another issue. Some users were unable to login to the portal (certificate authentication). After doing some research, we found that CN returned from LDAP query was replacing special characters with some others and consiquently the certificate CN and AD CN comparison was failing. We solved the problem by modifying the inc file.

    Is this a know issue, or am I missing something else?

    Kind regards, Grega

  2. Anonymous says:

    Thanks Ben. I finally got there. Installing on a test box now.

  3. Jason Jones says:

    Hi Ben,

    I saw this the other day when trying to create a HTTP-to-HTTPS redirect trunk on a new install, and assumed it was a bug introduced by the changes in U1 to provide customised trunk ports.

    Thanks for the heads up! 😉



  4. ColinPGolden says:

    Hello Ben,

    I had a similar problem when introducing a replacement array member following a hardware failure.

    I was not using custom ports, but got the same error. Deleting the redirect trunk, activating, then re-creating the redirect trunk fixed my problem.



  5. Jason Jones says:

    Hi Ben,

    You guys any closer to releasing this as a public fix?



  6. Andrew Zener says:

    I am now running into this issue.  Any word on a public fix?

  7. Ben Ari says:

    An official fix for this should be available soon, and will be announced on my blog, and the product team's blog.

  8. Ben Ari says:

    Hi Grega,

    The blog is not the appropriate platform to report or discuss issues. Please post your question in the public UAG forum. If that doesn't lead to a resolution, you can contact me directly via the "email blog author" above.

  9. Simon Day says:


    Was a bug fix ever released for this?



  10. Ben Ari says:

    Yes, Simon, this issue is addressed with Rollup 1 for UAG SP1 U1. You can read more about it here:…/uag-sp1-update-1-rollup-1-is-out.aspx


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