مفاهیم، انواع و معماری‌های شبکه‌های کامپیوتری

Types of VPN Architectures

1. Site-to-Site VPN

• Secure communication between branch offices over public internet
• Traffic encrypted with IPsec protocol
• No manual configuration required on end-user devices

2. Client-to-Site VPN

• Allows remote workers to securely connect to enterprise network
• Requires VPN client software
• Multi-factor authentication recommended

3. Clientless VPN

• Browser-based access using SSL/TLS encryption
• No need to install VPN software
• Ideal for limited, quick access

Split Tunnel vs Full Tunnel

• Split Tunnel: Corporate traffic via VPN, internet traffic direct
• Full Tunnel: All traffic routed through VPN for inspection
• Full Tunnel preferred for better security

Secure Protocols

TLS (Transport Layer Security)

• Modern replacement for SSL
• Use TLS 1.2 or higher for secure browser and VPN connections

SSH (Secure Shell)

• Encrypted alternative to Telnet for remote management
• Public key cryptography ensures secure authentication

Remote Access Solutions

Remote Desktop / RDP / RDP Gateway

• Graphical connection to remote desktops via RDP protocol
• Use RDP Gateway for secure SSL tunnels
• Firewall and certificate configuration required

VNC / Virtual Desktop

• Cross-platform desktop sharing using VNC protocol
• Virtual desktops hosted in the cloud for centralized management

Device Management Practices

Out-of-Band Management

• Control servers through dedicated interfaces (e.g., iLO, iDRAC)
• Remote access even when systems are powered off

Authentication & Authorization Controls

• Deploy AAA servers (e.g., RADIUS, TACACS+)
• Implement role-based access and 2FA

📋 Remote Access Security Overview Table

Solution	Description	Security Measures
Site-to-Site VPN	Branch office connection over public internet	IPsec, firewall rules
Client-to-Site VPN	Remote access for employees	2FA, VPN client software
Clientless VPN	Browser-based secure access	TLS 1.2+, limited access scope
RDP / Gateway	GUI access to remote desktop	SSL, port restrictions
VNC	Cross-platform desktop sharing	Encryption, IP filtering
Out-of-Band Management	Network-independent device control	Strong encryption, access limits