Answer: Execute the following code to get the list of port(s) that are associated with the database mirroring:
SELECT type_desc, port FROM sys.tcp_endpoints; GO
Answer: Execute the following code to confirm whether or not the endpoints are started:
SELECT state_desc FROM sys.database_mirroring_endpoints
Answer: Error 1418 is related to general network error. We have to make sure that the ports we will be using to establish database mirroring are available; also make sure that the firewall are not blocking them.