Port 1433 is the default port of SQL Server, and SQL Server service uses two ports: TCP- 1433 and UDP- 1434. Among them, 1433 is used for SQL Server to provide external services, and 1434 is used to return which TCP/IP port SQL Server uses to the requester. The security of 1433 port is not very high, and it is often easily compromised by hackers. Therefore, it is necessary to change the default port of SQL Server 1433. At present, there are many animations on the Internet to catch broilers with port 1433. Moreover, they often use sa weak passwords, so it is more complicated to set sa passwords. Do not use sa users for database connection in database link files such as conn. In addition, if only the local web links to the local database, there is no need to open port 1433 for remote link. If not, you can refer to some articles:/f/network/076/5/426259.htm.