Lync 2010 Mobility Autodiscover

Recently I have been configuring a Lync 2010 environment as a PoC for IM and presence for my company.

The PoC includes using IM and presence from the desktop and on mobile devices.  This requires an edge configuration and reverse proxy using TMG 2010.

I found the following blog post which is great for setting up mobility

Everything was configured included DNS names, certificates, software install etc.etc.

Once I had everything configured I found that if I tried to connect using my iPad device it would provide the following error message.

Can't connect to the server. It may be busy or temporarily unavailable. Please try again

I looked at the logging and found that the Lyncdiscover URL wasn't being redirected to the configuration file required to login.

Browsing to would simply produce a error 403 forbidden message.

I went to "more details" and turned auto config off and entered the following URL in the internal and external address (replace companyname with your relevant address!)

When visiting the above URL in Internet Explorer it will download a configuration file which contains the data required to login.

With this configured the logon worked.  This was fine, but I didn't want to provide a massive URL for configuration and wanted autoconfiguration working correctly.

My next stop was IIS URL rewrite rules on the server.  These are configured to redirect users with anything with lyncdiscover in the HTTP_HOST header to be redirected to the config file above.  I checked the rules and found they were all sound.  Also browsing on the localhost didn't redirect so I ruled out the TMG 2010 server being at fault.

Finally I went to add/remove programs and found the following entry.

Clicking repair on this resolved the issue for me.

When visiting I get the configuration file as if I were visiting

I hope this helps you!



  1. wow. That's the weirdest thing ever eh? Glad you fixed it. Never heard of that symptom.
    (via TechNet Forums)

  2. Tell me about it! I was racking my brains for ages trying to fix it!

  3. Having a similar problem but internal network wifi wont connect. We don't have a TMG and if I browse to (internally) - i dont get anything. Only works externally.

    External clients are fine connecting, its just internal. I suspect it's the hairpining. Any way to check?

    1. What is your setup like? If you have no TMG how are you enabling external access? It sounds like an IIS issue with dual network cards maybe
      Does http work?

  4. Mr Unknown, I have the exact opposite problem! Mine will work internally but I cannot for the life of me get it to connect externally.

    The oddest part, if I connect internally and then switch off my wifi and go to Mobile Data I'm still able to send and receive messages..

    Any clues Samuel?

    1. Hi Johnny

      Sounds like the autoconfig from remote is not working properly, especially if it works externally after internal config. Externally can you resolve ? If so what do you get?


  5. I don't see a prompt to save the configuration file, but after that I am still not able to login. I don't see the "more details" either. Any ideas? I am still getting the 403 forbidden for my internal... thanks!

  6. You should see a prompt for the configuration file? How about if you browse to the full path externally?

    Does this provide a cfg file?

    On Android you must press the option key to get the "More Options" button. On iOS, it is underneath the logon name.

  7. i get "The resource cannot be found." when trying to access

  8. I checked the IIS console and found that there is no URL rewrite rule for autodiscover.
    How can I create URL rewrite rules for redirect autodiscover ?
    Should I repair the "IIS URL Rewrite Module 2"component on front end server ?

    1. Hi Sadegh

      Yes, hit repair on the IIS URL Rewrite Module on the Front End server.


  9. I repaired that component but nothing was changed.

  10. This was a life saver. Thanks for your help. I've been beating my head against my desk for a couple of days about this.

  11. Solved my problem and my Chistmas. Thanks!


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