4
Unassigned
Low RiskTCP/UDP — System & Infrastructure
Port Overview
Port Number
4
Service Name
Unassigned
Transport Protocol
TCP/UDP
Category
System & Infrastructure
Security Risk
Low
Port Range
Well-Known (0-1023)
What is Port 4?
Port 4 is unassigned in the IANA registry. It has no official protocol assignment and should not be used for production services.
TCP/UDP
System & Infrastructure
Security Considerations
Port 4 (Unassigned) is classified as low risk. This service uses encryption or has a minimal attack surface, making it relatively safe to expose.
Recommendation: Standard security practices apply. Keep software updated and monitor access.