Any comments in the error.log file? Which version MWG 6 or 7?
No, error.log - is clear.
I've seen this appening because of two diffrent situations:
1st. The appiances stopped contacting the domain controllers therefore not authentication occoured and it had the mapping option to block connections. (if no mapping occured)
2st. The av. engine had a problem...... but I have no more info on this one.
We have 3 different auth method:
1. access to some urls - without of authorization
2. access from some ip - by ip address
3. By AD
So i think that the second situation is more realistic but this is very bad - appliances must work 24x7.