Port 1434

Q: What is port 1434?

SQL Server Browser — instance discovery service UDP port 1434 is used by the SQL Server Browser Service to help clients locate named SQL Server instances and their dynamic ports. The SQL Slammer worm (2003) exploited a vulnerability on this port and became one of the fastest-spreading pieces of malware in history, saturating internet bandwidth within minutes. This port must always be blocked at the internet perimeter.

MS-SQL-M

SQL Server Browser — instance discovery service

Port

1434

Protocol

UDP

Service

MS-SQL-M

Security

Dangerous

Full name: Microsoft SQL Server Browser

What is port 1434?

UDP port 1434 is used by the SQL Server Browser Service to help clients locate named SQL Server instances and their dynamic ports. The SQL Slammer worm (2003) exploited a vulnerability on this port and became one of the fastest-spreading pieces of malware in history, saturating internet bandwidth within minutes. This port must always be blocked at the internet perimeter.

Related ports

← All ports