Community hub
Recent from talks
Knowledge base stats:
Talk channels stats:
Members stats:
Server Message Block
Server Message Block (SMB) is a communication protocol used to share files, printers, serial ports, and miscellaneous communications between nodes on a network. On Windows, the SMB implementation consists of two vaguely named Windows services: "Server" (ID: LanmanServer) and "Workstation" (ID: LanmanWorkstation). It uses NTLM or Kerberos protocols for user authentication. It also provides an authenticated inter-process communication (IPC) mechanism.
SMB was originally developed in 1983 by Barry A. Feigenbaum at IBM to share access to files and printers across a network of systems running IBM PC DOS. In 1987, Microsoft and 3Com implemented SMB in LAN Manager for OS/2, at which time SMB used the NetBIOS service atop the NetBIOS Frames protocol as its underlying transport. Later, Microsoft implemented SMB in Windows NT 3.1 and has been updating it ever since, adapting it to work with newer underlying transports: TCP/IP and NetBT. SMB over QUIC was introduced in Windows Server 2022.
In 1996, Microsoft published a version of SMB 1.0 with minor modifications under the Common Internet File System (CIFS /sɪfs/) moniker. CIFS was compatible with even the earliest incarnation of SMB, including LAN Manager's. It supports symbolic links, hard links, and larger file size, but none of the features of SMB 2.0 and later. Microsoft's proposal, however, remained an Internet Draft and never achieved standard status. Microsoft has since discontinued the CIFS moniker but continues developing SMB and publishing subsequent specifications. Samba is a free software reimplementation of the SMB protocol and the Microsoft extensions to it.
Server Message Block (SMB) enables file sharing, printer sharing, network browsing, and inter-process communication (through named pipes) over a computer network. SMB serves as the basis for Microsoft's Distributed File System implementation.
SMB relies on the TCP and IP protocols for transport. This combination allows file sharing over complex, interconnected networks, including the public Internet. The SMB server component uses TCP port 445. SMB originally operated on NetBIOS over IEEE 802.2 - NetBIOS Frames or NBF - and over IPX/SPX, and later on NetBIOS over TCP/IP (NetBT), but Microsoft has since deprecated these protocols. On NetBT, the server component uses three TCP or UDP ports: 137 (NETBIOS Name Service), 138 (NETBIOS Datagram Service), and 139 (NETBIOS Session Service).
In Microsoft Windows, two Windows services implement SMB. The "Server" service (ID: LanmanServer) is in charge of serving shared resources. The "Workstation" service (ID: LanmanWorkstation) maintains the computer name and helps access shared resources on other computers. SMB uses the Kerberos protocol to authenticate users against Active Directory on Windows domain networks. On simpler, peer-to-peer networks, SMB uses the NTLM protocol.
Windows NT 4.0 SP3 and later can digitally sign SMB messages to prevent some man-in-the-middle attacks. SMB signing may be configured individually for incoming SMB connections (by the "LanmanServer" service) and outgoing SMB connections (by the "LanmanWorkstation" service). The default setting for Windows domain controllers running Windows Server 2003 and later is to not allow unsigned incoming connections. As such, earlier versions of Windows that do not support SMB signing from the get-go (including Windows 9x) cannot connect to a Windows Server 2003 domain controller.
SMB supports opportunistic locking (see below) on files in order to improve performance. Opportunistic locking support has changed with each Windows Server release.
Hub AI
Server Message Block AI simulator
(@Server Message Block_simulator)
Server Message Block
Server Message Block (SMB) is a communication protocol used to share files, printers, serial ports, and miscellaneous communications between nodes on a network. On Windows, the SMB implementation consists of two vaguely named Windows services: "Server" (ID: LanmanServer) and "Workstation" (ID: LanmanWorkstation). It uses NTLM or Kerberos protocols for user authentication. It also provides an authenticated inter-process communication (IPC) mechanism.
SMB was originally developed in 1983 by Barry A. Feigenbaum at IBM to share access to files and printers across a network of systems running IBM PC DOS. In 1987, Microsoft and 3Com implemented SMB in LAN Manager for OS/2, at which time SMB used the NetBIOS service atop the NetBIOS Frames protocol as its underlying transport. Later, Microsoft implemented SMB in Windows NT 3.1 and has been updating it ever since, adapting it to work with newer underlying transports: TCP/IP and NetBT. SMB over QUIC was introduced in Windows Server 2022.
In 1996, Microsoft published a version of SMB 1.0 with minor modifications under the Common Internet File System (CIFS /sɪfs/) moniker. CIFS was compatible with even the earliest incarnation of SMB, including LAN Manager's. It supports symbolic links, hard links, and larger file size, but none of the features of SMB 2.0 and later. Microsoft's proposal, however, remained an Internet Draft and never achieved standard status. Microsoft has since discontinued the CIFS moniker but continues developing SMB and publishing subsequent specifications. Samba is a free software reimplementation of the SMB protocol and the Microsoft extensions to it.
Server Message Block (SMB) enables file sharing, printer sharing, network browsing, and inter-process communication (through named pipes) over a computer network. SMB serves as the basis for Microsoft's Distributed File System implementation.
SMB relies on the TCP and IP protocols for transport. This combination allows file sharing over complex, interconnected networks, including the public Internet. The SMB server component uses TCP port 445. SMB originally operated on NetBIOS over IEEE 802.2 - NetBIOS Frames or NBF - and over IPX/SPX, and later on NetBIOS over TCP/IP (NetBT), but Microsoft has since deprecated these protocols. On NetBT, the server component uses three TCP or UDP ports: 137 (NETBIOS Name Service), 138 (NETBIOS Datagram Service), and 139 (NETBIOS Session Service).
In Microsoft Windows, two Windows services implement SMB. The "Server" service (ID: LanmanServer) is in charge of serving shared resources. The "Workstation" service (ID: LanmanWorkstation) maintains the computer name and helps access shared resources on other computers. SMB uses the Kerberos protocol to authenticate users against Active Directory on Windows domain networks. On simpler, peer-to-peer networks, SMB uses the NTLM protocol.
Windows NT 4.0 SP3 and later can digitally sign SMB messages to prevent some man-in-the-middle attacks. SMB signing may be configured individually for incoming SMB connections (by the "LanmanServer" service) and outgoing SMB connections (by the "LanmanWorkstation" service). The default setting for Windows domain controllers running Windows Server 2003 and later is to not allow unsigned incoming connections. As such, earlier versions of Windows that do not support SMB signing from the get-go (including Windows 9x) cannot connect to a Windows Server 2003 domain controller.
SMB supports opportunistic locking (see below) on files in order to improve performance. Opportunistic locking support has changed with each Windows Server release.