Back-To-My-Mac connecting as "Guest"

Subscribers to MobileMe have the option to enable the "Back to my Mac" feature, which is a dynamic-DNS service that uses the MobileMe account to establish a constant connection between authenticated computers. Users may run into a problem where this connection recognizes the computer but authenticates as "guest", instead of the computer's account.

Apple Discussions poster EmanueleC writes:

"I want to access my iMac from my Macbook, here on the home network setup via an Airport Extreme Base station. I have followed the directions carefully to setup BTMM. I can see the iMac on the Finder window but when I try to connect it says: Connected as Guest! And I cannot see any files!"

This issue may be caused by several things, and there are several suggestions users can try in order to get "Back to my Mac" to function properly.

Workaround and Fix

Manually connect to the shared computer The Finder provides options to manually connect to shared computers through both Screen Sharing and File Sharing services. With the remote computer selected in the Finder sidebar, click "Connect As..." to bring up an authentication window and log in with a proper username for that computer (not the MobileMe login information). Clicking "Remember this password in my keychain" should keep the authentication information for the next session. This is technically a workaround for the problem, since the computer is using Back to My Mac to establish a connection but then uses network password to authenticate, instead of authenticating through MobileMe.

Other Potential Fixes

Restart MobileMe The first thing to try is to restart the MobileMe connection and associated services on the affected computers, which should refresh any expired certificates used to authenticate the connections. To do this, open the "MobileMe" system preferences and click "Stop" under the "Back to My Mac" tab. Then under the "Account" tab click the "Sign Out..." button and log out of MobileMe. After MobileMe is inactive, go to the "Sharing" system preferences and uncheck both the "File Sharing" and "Screen Sharing" (or "Remote Management") services. Then restart the computer, and re-enable the services and "Back to My Mac", and try the connection again.

Remove .Mac/.Me Keychain entries The keychain contains several keys and passwords used by MobileMe. The authentication to the MobileMe services can be reset by removing the keychain items associated with the service. The keys to look for are those pertaining to ".Mac sharing" (login keychain), "username.members.mac.com" (system keychain), and also the "network passwords" used for any of the computers being used in the BTMM connection. Additionally, remove any expired certificates (the ones with the red X next to them). With these items removed, users should follow the procedure above to reset MobileMe.

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