Port 9051

Overview:

Tor is both a network and a set of technologies facilitating anonymous communication on the Internet. It routes Internet traffic through a worldwide, volunteer overlay consisting of thousands of relays.

Port 9051 Purpose:

Port 9051 is the default Control Port of a Tor instance. Unlike the SOCKS proxy port (commonly 9050), the Control Port allows external applications to communicate with Tor via the Tor Control Protocol. This protocol enables authenticated clients to:

• Manage and configure Tor on the fly
• Query status and network information
• Gracefully shut down or restart Tor
• Create ephemeral hidden services on demand

Protocols and Characteristics:

• The Control Port runs over TCP and supports either plaintext connections (optionally with hashed password authentication) or, increasingly, UNIX domain sockets for local secured access.
• Because Tor does not natively employ SCTP, port 9051 only supports TCP.
• Authentication can be via cookie or password and is essential to prevent unauthorized Tor manipulation.