SMB protocol versions

SMB 1.0 (CIFS)

SMB 1.0, also known as CIFS (Common Internet File System), was the original implementation of the Server Message Block protocol introduced in the 1990s. It provides basic file sharing, printer sharing, and named pipe services.

Key Features

File and printer sharing over LAN
Simple authentication (LM, NTLM)
Extended attributes via NTFS

Typical Use Cases

Legacy Windows NT/2000 environments
Embedded devices with limited resources

Sample Configuration

# Enable SMB1 on Windows Server
Set-SmbServerConfiguration -EnableSMB1Protocol $true

# Verify SMB1 status
Get-SmbServerConfiguration | Select-Object EnableSMB1Protocol

⚠️ Microsoft recommends disabling SMB1 due to security vulnerabilities. See the FAQ for guidance.

SMB 2.0 / 2.1

Introduced with Windows Vista and Windows Server 2008, SMB 2.0 dramatically improved performance and added support for larger buffers, pipelining, and larger file sizes.

Enhancements Over SMB 1.0

Reduced command overhead (compound requests)
Support for 64‑KB buffers (up from 4 KB)
Improved durability with durable handles (SMB 2.1)

Sample Code (PowerShell)

# Enable SMB2 only
Set-SmbServerConfiguration -EnableSMB2Protocol $true -EnableSMB1Protocol $false

# List active SMB dialects
Get-SmbServerConfiguration | Format-List EnableSMB2Protocol,EnableSMB1Protocol

Compatibility Matrix

OS	SMB 2.0 Support	SMB 2.1 Support
Windows 7 / Server 2008 R2	✓	✓
Windows 8 / Server 2012	✓	✓
Windows 10 / Server 2016	✓	✓

SMB 3.0 – 3.1.1

SMB 3.x, introduced with Windows 8/Server 2012, adds security enhancements such as encryption, multi-channel, and improved resiliency for cloud and hyper‑V scenarios.

Major Features

End‑to‑end encryption (AES‑128‑CCM)
Multichannel – simultaneous use of multiple network interfaces
Continuous availability (SMB 3.0) and transparent failover (SMB 3.0)
SMB Direct (RDMA) for ultra‑low latency
SMB 3.1.1 – pre‑authentication integrity (SHA‑256)

Enabling Encryption

# Require encryption on a specific share
Set-SmbShare –Name "SecureDocs" –EncryptData $true

# Verify encryption status
Get-SmbShare –Name "SecureDocs" | Select-Object Name,EncryptData

Performance Comparison

Metric	SMB 2.1	SMB 3.0	SMB 3.1.1
Max Throughput (Gbps)	5	10	12
Encryption Overhead	~5%	~3%	~2%
Latency (us)	120	80	70

For detailed migration guidance see the Migration Guide.