## What runs on port 445?

Port 445 is a well-known port number associated with the Microsoft Server Message Block (SMB) protocol. It is primarily used for file and printer sharing in Windows-based networks. SMB is a client-server protocol that allows computers to access shared resources on a network, such as files, folders, printers, and other devices.

**SMB operates on the following principles:**

* Client-server architecture: SMB uses a client-server architecture, where a client computer initiates a request to access a shared resource on a server computer.
* Request-response model: The client sends a request message to the server, which then processes the request and sends a response message back to the client.
* File and printer sharing: SMB is primarily used for sharing files and printers on a network. It allows users to access and modify files stored on a server computer as if they were stored locally on their own computer.

SMB's primary functions include:

* File sharing: SMB allows users to share files and folders with other users on the network. Users can grant different levels of access permissions, such as read-only or read-write access.
* Printer sharing: SMB enables users to share printers connected to a server computer with other users on the network. Users can print documents remotely from their own computers without having to physically connect to the printer.
* Remote administration: SMB can be used for remote administration of Windows-based computers. Administrators can access and manage files, services, and other resources on remote computers over the network.

Security considerations:

SMB has been a target of cyberattacks due to its widespread use and potential vulnerabilities. It is important to implement strong security measures when using SMB, such as:

* Strong passwords: Use strong passwords for user accounts to prevent unauthorized access.
* Firewall: Configure firewalls to block unauthorized access to port 445 from external networks.
* SMB signing: Enable SMB signing to ensure the integrity and authenticity of SMB messages.
* SMB encryption: Encrypt SMB traffic to protect data from eavesdropping and interception.

Alternatives to SMB:

While SMB is a widely used protocol for file and printer sharing, there are alternative protocols available, such as:

* Network File System (NFS): NFS is a protocol used for file sharing in Unix-based systems.
* Apple Filing Protocol (AFP): AFP is a protocol used for file sharing in Apple Macintosh systems.
* FTP (File Transfer Protocol): FTP is a protocol used for transferring files between computers over a network.

The choice of protocol depends on the specific requirements and environment of the network.

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This combination of NetBIOS over TCP/IP is known as NetBT and uses UDP ports 137 and 138 and TCP port 139. Win2K introduced the ability to run SMB directly over TCP/IP without the NetBIOS layer. This new direct TCP/IP SMB runs over port 445 and is the preferred method for running SMB.read more >>