SSH

Remote services allow users and administrators to interact with systems over a network.

Without remote services, administrators would need physical access to every machine they manage.

In modern environments, remote administration is a fundamental requirement.

Common Uses

Remote services are commonly used to:

• Administer servers
• Transfer files
• Execute commands
• Manage applications
• Troubleshoot systems
• Provide remote access to users

SSH

SSH (Secure Shell) is the most common remote administration protocol on Linux systems.

Default port:

22/tcp

SSH provides:

• Remote command execution
• Interactive shells
• File transfer capabilities
• Secure encrypted communication

Example:

ssh user@10.10.10.10

Successful authentication typically results in an interactive shell.

RDP

Remote Desktop Protocol (RDP) is Microsoft's graphical remote administration protocol.

Default port:

3389/tcp

Unlike SSH, RDP provides a full graphical desktop.

Administrators frequently use RDP to:

• Manage Windows servers
• Configure applications
• Perform troubleshooting
• Access graphical tools

Example:

mstsc.exe

WinRM

Windows Remote Management (WinRM) is Microsoft's remote management framework.

Default ports:

5985/tcp (HTTP)
5986/tcp (HTTPS)

WinRM allows administrators to:

• Execute PowerShell commands remotely
• Open remote PowerShell sessions
• Automate administrative tasks

Example:

Enter-PSSession -ComputerName SERVER01

WinRM is heavily used by administrators and automation platforms.

SMB

Server Message Block (SMB) is primarily used for file sharing.

Common ports:

445/tcp
139/tcp

SMB allows:

• Access to shared folders
• Printer sharing
• File transfers
• Various Windows management functions

Example:

\\SERVER01\Share

Although SMB is not primarily a remote shell protocol, it plays a major role in Windows environments.

VNC

Virtual Network Computing (VNC) provides graphical remote desktop access.

Common ports:

5900/tcp+

VNC is platform independent and may be encountered on:

• Linux systems
• Embedded devices
• Legacy environments

Web-Based Administration

Many modern systems expose administrative interfaces through a web browser.

Examples include:

• Hypervisors
• Network appliances
• Cloud platforms
• Security products
• Internal applications

Common ports:

80/tcp
443/tcp

A web interface may ultimately provide capabilities equivalent to SSH or RDP.

Authentication

Remote services usually require authentication.

Common mechanisms include:

• Username and password
• Kerberos
• Certificates
• SSH keys
• Multi-factor authentication (MFA)

The authentication method often determines how difficult a service is to access or abuse.

Common Ports

Memorization is not important. Over time these ports become familiar through repeated exposure.