Mirroring SQL error log - Error: 8474, State: 11
The mirror state is likely confused at this point and should not be trusted. cherish.j.wang posted the following at: http://www.sqlservercentral.com/Forums/Topic1237273-1549-1.aspx

use master
GO
alter endpoint endpoint_name state = stopped;
GO
alter endpoint endpoint_name state = started;
GO


In that same discussion Robert Davis (SQL Soldier) agreed that would resolve the problem for the moment.  But he also pointed out that if you use the fully qualified domain name of the servers you are less likely to run into a name resolution error.

UPDATE: When you reset the endpoints, it will take the database offline for the duration of the restart.  However, it will not break the mirror.  The mirroring will stop running when the endpoint is stopped, but it will resume once the endpoint is again started.

The MSDN article: http://support.microsoft.com/kb/2490051 suggests.


Run these commands on the primary
If it does not resolve the problem, run the commands on the mirror.
If the database becomes SUSPENDED run ALTER DATABASE &lt;Database Name&gt; SET PARTNER RESUME