Owen

SQL Server is a popular database management system (DBMS) that is used by organizations of all sizes and shapes. As such, SQL Server is often deployed on servers that are connected to the internet.

Because SQL Server is used by so many organizations, it is important that the firewall on the servers that it is running on is open so that it can communicate with the internet. SQL Server can communicate with the internet using a number of different ports. The following are the ports that SQL Server needs to be open in order to communicate with the internet:

TCP port 1433
UDP port 1434
TCP port 1435
UDP port 1234

SQL Server also needs to be open in order to communicate with the other servers that it is running on. For example, if SQL Server is running on a server that is also running Microsoft Office, then SQL Server needs to be open in order to communicate with the other servers that are running on that server.