Port 1434 — MSSQL Browser

UDP · Port 1434/UDP is used by the Microsoft SQL Server Browser service, which helps clients connect to a SQL Server instance. This service provides information about available instances and allows clients to query for specific instances. Security relevance: enabling this service can increase attack surface as it provides information about SQL Server instances.

Port Number: 1434
Service Name: MSSQL Browser
Protocol: UDP
Common Software: SQL Server Browser

Security Notes

Review IANA registry for port 1434 usage. Apply principle of least privilege - only open ports that are required.

FAQ

What is port 1434 used for?

Port 1434 is used for MSSQL Browser. Port 1434/UDP is used by the Microsoft SQL Server Browser service, which helps clients connect to a SQL Server instance. This service provides information about available instances and allows clients to query for specific instances. Security relevance: enabling this service can increase attack surface as it provides information about SQL Server instances. Common software: SQL Server Browser.

Is port 1434 dangerous to leave open?

Review IANA registry for port 1434 usage. Apply principle of least privilege - only open ports that are required.

How do I check if port 1434 is open?

Use nmap: nmap -p 1434 <target> or check locally: ss -tlnp | rg 1434