SQL Conectivity error (1418) on SQL Mirroring in SQL Server_2014 Enterprises

Question

I perform this subjected task/activity in DOMAIN environment with Multiple VPN.
No matter what I try, I constantly run into a 1418 error, I've check all my tcp/ip configs both in sql,
and the server 2012 os, on both vms/physical machine.  I’ve
enabled tcp/ip filtering and allowed all connections, rulessets in firewall, I’ve used telnet to connect up.  Nothing
seems to work.  Each
server can ping the other, they can telnet into 5022, & 5023 as well. I don’t know where to proceed from here.  Is
there some config somewhere or issues with vms that I am not seeing?  All
the machines in the mirroring array are server 2012 with same SQL 2014 Ent edition. Now please guide as what can we do to go at next Step....!
Regards,
Zeeshan

Answer 1

Hi Zeeshan,
Please check the following, have you checked the error log? Share the error screenshot here in order to verify the issue.
Make sure that the mirror database is ready for mirroring.
Make sure that the name and port of the mirror server instance are correct.
Make sure that the destination mirror server instance is not behind a firewall.
Make sure that the principal server instance is not behind a firewall.
Verify that the endpoints are started on the partners by using the state or state_desc column the of the sys.database_mirroring_endpoints catalog view. If either endpoint is not
started, execute an ALTER ENDPOINT statement to start it.
Make sure that the principal server instance is listening on the port assigned to its database mirroring endpoint and that and the mirror server instance is listening on its port. For more information, see "Verifying Port Availability," later in this
topic. If a partner is not listening on its assigned port, modify the database mirroring endpoint to listen on a different port.