# SMB - Port 445

# Concepts

Server Message Block (SMB) is a communication protocol for providing shared access to files, printers, and serial ports between nodes on a network. It also provides an authenticated inter-process communication mechanism.

Key Technical Details:

• NetBIOS: Older versions ran over NetBIOS (ports 135-139). Modern SMB runs directly over TCP port 445.
• Dialects: CIFS is a specific dialect of SMB.
• Signing: Prevents man-in-the-middle attacks, but often disabled for performance.