137
NetBIOS Name
High RiskUDP — System & Infrastructure
Port Overview
Port Number
137
Service Name
NetBIOS Name
Transport Protocol
UDP
Category
System & Infrastructure
Security Risk
High
Port Range
Well-Known (0-1023)
What is Port 137?
NetBIOS Name Service. Resolves NetBIOS names to IP addresses on local networks. Part of the legacy Windows networking stack and a frequent attack vector.
UDP
System & Infrastructure
Commonly Used
Security Considerations
Port 137 (NetBIOS Name) is classified as high risk. This port is a common target for automated scanning and brute-force attacks. If you must expose it, restrict access to known IP addresses.
Recommendation: Use firewall rules to whitelist trusted IPs. Enable rate limiting and intrusion detection.