IT-Hub

Telnet:

Uses TCP port 23.
Designed for remote terminal access without encryption.

SSH:

Uses TCP port 22.
Designed for secure remote login and command ex*****on.

Comparison of OSI and TCP/IP Models
- OSI has 7 layers; TCP/IP has 4 layers.
- OSI is a theoretical model; TCP/IP is practical and widely used.
- OSI separates presentation and session layers; TCP/IP combines them into the application
layer.

Common network devices include:
- Router: Connects different networks and routes data.
- Switch: Connects devices within the same network and forwards data intelligently.
- Hub: Broadcasts data to all devices; less efficient than a switch.
- Access Point: Provides wireless access to a wired network.
- Firewall: Monitors and controls incoming and outgoing network traffic based on security rules.

Spanning Tree Protocol (STP)
همدا پروتوکول په Layer 2 Devices کې کار کوې لکه بریج او سويچ ، IEEE 802.1D پوری ارتباط لری.
په ساده ډول به ووایم وظیفه یی دا ده چې په یو نیټ ورک کې د Loop مخه نیسی Loop بیا د Redundancy په صورت کې رامنځته کیږي. Redundancy مطلب له یو څخه زیاتی لاری د معلوماتو د لیږلو لپاره درلودلو ته Redundancy وایي.