Port
Port 137 — NetBIOS name
Port 137 (UDP) is used by NetBIOS name. NetBIOS Name Service (legacy Windows networking).
Port 137 at a glance
| Property | Value |
|---|---|
| Port number | 137 |
| Transport | UDP |
| Service | NetBIOS name |
| Category | Well-known port |
What it is used for
NetBIOS Name Service (legacy Windows networking).
Security considerations
Block from the internet; information-disclosure risk.
See our full TCP/UDP port reference and learn how firewalls filter ports in the CyberOps course.
Frequently asked questions
What is port 137 used for?
Port 137 (UDP) is used by NetBIOS name. NetBIOS Name Service (legacy Windows networking).
Is port 137 TCP or UDP?
Port 137 uses UDP.
Is it safe to open port 137?
Block from the internet; information-disclosure risk.
Related
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