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I have a NAS LACIE 2Tb BigDisk server.

I can't connect to the disk as I get the following error:

enter image description here

This didn't happen in Snow Leopard. How can I solve this?

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Also a problem with QNAP firmware 3.4.4 (which was released after Lion gone wild!) – Hugo Aug 10 '11 at 22:32
up vote 4 down vote accepted

Mac OS X Lion doesn't support the authentication DHCAST128 anymore (for security reasons apparently).

To reactivate it, you need to enter the following lines of code in Terminal:

sudo chmod o+w /Library/Preferences
defaults write /Library/Preferences/ afp_host_prefs_version -int 1

After a restart, you should try to connect to the NAS through an AFP-Share (which will give you an Error Message again). A new connection profile should now have appeared in your "/Library/Preferences". Now you only need to enter the following commands to enable DHCAST128 support:

sudo defaults write /Library/Preferences/ afp_disabled_uams -array "Cleartxt Passwrd" "MS2.0" "2-Way Randnum exchange"
sudo chmod o-w /Library/Preferences

After another restart, the NAS connection should work.

In case you want to desactive DHCAST128 autentication again you need to type the following line:

sudo defaults write /Library/Preferences/ afp_disabled_uams -array-add "DHCAST128"
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