I'm a little skeptical of the concerns regarding the AD going down. In our environment, if that happened nobody would be able to use their workstations and they wouldn't be able to use any applications that use the database. I suppose if a web server was using a database you wouldn't want it's logins to authenticate against the AD, but I'm thinking of putting all web facing databases on a separate server - away from sensitive data.
Interesting nonetheless.
Windows caches the login credentials so users could still likely log into their workstations. Easy way to test this is to log out of your machine, unplug the network cable and then log in again. It will likely succeed.
I am going to try this with SQL later on today as I am curious about that. If it works, I'm going to be bumping a lot of our servers out of mixed mode.
That's what I meant earlier. Another thought I just had and can't test now is what if you had a local account on that server in addition to your domain account? That could be another avenue.
Sue