651
IEEE-MMS
High RiskTCP/UDP — Other
Port Overview
Port Number
651
Service Name
IEEE-MMS
Transport Protocol
TCP/UDP
Category
Other
Security Risk
High
Port Range
Well-Known (0-1023)
What is Port 651?
IEEE Manufacturing Message Specification (MMS), defined in ISO 9506, used in industrial automation and SCADA systems. Exposure on public networks poses significant ICS security risk.
TCP/UDP
Other
Security Considerations
Port 651 (IEEE-MMS) 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.