Samba

SMB (Samba)

SMB - "Server Message Block" - is a file sharing protocol that was invented by IBM and has been around since the mid-eighties.

SMB is a protocol meaning an agreed upon way of communicating between systems over a local area network (LAN).

Most modern storage systems no longer use CIFS, they use SMB 2 or SMB 3 and NFS “Network File System”

SMB vs CIFS

CIFS - “Common Internet File System.”- is a particular implementation of the Server Message Block protocol by Microsoft. someone said CIFS is a dialect of SMB. cause SMB version 1 is often associated with CIFS. This is because CIFS is a popular 1996 Microsoft SMB dialect that implemented SMB on many networks.

Because CIFS is a form of SMB, a client speaking CIFS can talk to a server speaking SMB and vice versa. While they are the same top level protocol, there are still differences in implementation and performance tuning

SMB Protocol

SMB works at Layer 7 and the packets are in three types session control packets, file access packets and general message packets. The application layer, and uses TCP/IP on port 445 (note: prior to Windows 2000 the SMB port number was 139).

SMB Version

Version	Description	Limitation
SMB1	SMBv1 is the original implementation of SMB. It was created at IBM in the 1980s.	SMB1 used 16-bit packet and small. by today’s standards data buffers is limited in performance. SMBv1 does not have any encryption, which makes it so unsecured. Therefore it shouldn’t be used today. The protocol is highly susceptible to MITM (man-in-the-middle) attacks SMBv1 is the protocol exploited by ransomware like WannaCry and NotPetya. SMB1 is inefficient and creates a lot of network “chatter” when compared to newer SMB versions
SMB2	SMB 2.0 was released by Microsoft in 2006 with Windows Vista SMB 2.1 was released by Microsoft in 2008 with Windows Server 2008 R2 and Windows 7
SMB3	SMB 3.0 adds more performance and security enhancements to the protocol such as SMB multichannel and end-to-end encryption. SMB 3.1.1 — the latest version of SMB — was released along with Windows Server 2016 and Windows 10 to include security enhancements such as: enforcing secure connections with newer (SMB2 and later) clients and stronger encryption (AES-256 from Windows 11 and Windows Server 2022).

This page provides detailed SMB features.