66
Oracle SQL*NET
Low RiskTCP/UDP — Database
Port Overview
Port Number
66
Service Name
Oracle SQL*NET
Transport Protocol
TCP/UDP
Category
Database
Security Risk
Low
Port Range
Well-Known (0-1023)
What is Port 66?
Port 66 was historically associated with Oracle SQL*NET, an early version of Oracle's proprietary network protocol for database communication before it migrated to port 1521. This port is largely unused today as Oracle Net Services standardized on higher port numbers.
TCP/UDP
Database
Security Considerations
Port 66 (Oracle SQL*NET) 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.