What port does SMB CIFS use?

SMB has always been a network file sharing protocol. As such, SMB requires network ports on a computer or server to enable communication to other systems. SMB uses either IP port 139 or 445.

What traffic uses port 445?

Today, port 445 is used by Microsoft Directory Services for Active Directory (AD) and for the Server Message Block (SMB) protocol over TCP/IP.

Does SMB use CIFS?

With the high-level pre-authentication checks during the file transfer, SMB took it over CIFS. In the world of windows OS, SMB is most likely to be used. SMB2 is standard for Windows Vista 2006, and SMB3 is used for Windows 8 and Windows Server 2012.

What is SMB CIFS in networking?

In computer networking, Server Message Block (SMB), one version of which was also known as Common Internet File System (CIFS /sɪfs/), is a communication protocol for providing shared access to files, printers, and serial ports between nodes on a network.

What is SMB port 445 used for in Windows?

Simply put, port 445 is used for file sharing over the network by windows. Microsoft made a change to run SMB over port 445 from Windows 2000. Port 445 is used by Microsoft directory services, known as Microsoft-DS. Port 445 is used by both TCP and UDP protocols for several Microsoft services.

What’s the difference between ports 139 and 445 in SMB?

SMB ports are generally port numbers 139 and 445. Port 139: Used by SMB dialects that communicate over NetBIOS, a transport layer protocol designed to use in Windows operating systems over a network. Port 445: Used by newer versions of SMB (after Windows 2000) on top of a TCP stack, allowing SMB to communicate over the Internet.

When to block outbound SMB TCP 445 traffic?

Description: Blocks all outbound SMB TCP 445 traffic when on an untrusted network Note Small office and home office users, or mobile users who work in corporate trusted networks and then connect to their home networks, should use caution before they block the public outbound network.

Is the Windows firewall allowing inbound SMB traffic?

Note The Windows Firewall has blocked all inbound SMB communications by default since Windows XP SP2 and Windows Server 2003 SP1. Windows devices will allow inbound SMB communication only if an administrator creates an SMB share or alters the firewall default settings.