Getting Error 64 When Trying To Connect to SQL Server or Azure 

Often times when working with a client, I’ll run into issues or get emails from a client with a message like the following:

A connection was successfully established with the server, but then an error occurred during the pre-login handshake. (provider: TCP Provider, error: 0 – The specified network name is no longer available.) (Microsoft SQL Server, Error: 64)

In 100% of the cases that I’ve seen this message, it is either a firewall issue on the client side by not being allowed out of their corporate network to the database server, or an issue with the destination side not allowing the client IP to connect.

In both situations, it is a firewall/security issue either on the client or server side by not allowing access. In cases like this, an email or ticket to the group that administers the network security should get this resolved.

If you’ve encountered this issue and need to submit a trouble ticket, please include your source IP and destination that you are trying to access. If you know the ports, please include those as well. Typically SQL Server is port 1433. This will greatly help the network team get this resolved for you.