Starting Mirroring after GUI configuration you receive the error “One or more of server network addresses lack a fully qualified domain name (FQDN). Specify the FQDN for each server, and click Start Mirroring again.”
This error occur because server cannot qualify computername (example 2 server on workgroup without dns configured).
In this case when you reach the following dialogbox
At the end if you start mirroring will function correctly.
PS forcing FQDN with host file resolution don’t function.