To which port does the SMB protocol relate?

The SMB (Server Message Block) protocol is primarily used for file sharing, printing services, and other network communications in Windows environments. The correct association of SMB is with TCP port 445. This port is crucial for SMB over TCP, which enables it to function across various types of networks without needing NetBIOS.

Prior to the use of TCP port 445 for SMB, older implementations used port 137, 138, and 139 for NetBIOS over TCP/IP, but these are now largely superseded by the direct use of TCP port 445. This makes port 445 the standard for modern SMB communications, particularly in enterprise networks where efficiency and security are paramount.

In contrast, the other ports mentioned are associated with different protocols. UDP port 123 is utilized for Network Time Protocol (NTP), TCP port 636 is for LDAP over SSL/TLS, and TCP port 22 is designated for Secure Shell (SSH) connections. Each of these serves distinct functions and does not support SMB traffic.