Database Mirroring fighting with DocAve

Here's a weird one… while trying to set up DB mirroring of a content database colocated with a SharePoint contentDB, I got the following error:

"The server network address “TCP://SQLServer:5023″ can not be reached or does not exist. Check the network address name and that the ports for the local and remote endpoints are operational"

Turned out that the client had previously installed DocAve, which creates a SQL mirroring endpoint that only supports certificates, not Windows Authentication. This was a pain to find, but easy to fix. Simply use SQL Server Management Studio to connect to your principal and mirror servers, expand Server Object, EndPoints, then Database Mirroring. If there's an existing endpoint, script it as drop & create (in 2008 - for 2005 you need to script the drop and create seperately). Check the authentication component of the script: if you see "CERTIFICATE" and the name of a certificate (possibly similar to DocAve{ID}) then you can simply add the term WINDOWS before CERTIFICATE to allow both Windows & Certificate based authentication. This will let you proceed with manual mirroring and preserve DocAve. Note: the full syntax allows you to specify the type of Windows authentication with a second keyword. Leaving it blank implies NEGOTIATE.