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OSI Model Interactive Learning

Current Flow

Direction: Sender → Receiver

Processing Layer 7

Real-World Example

User clicks "Login" button → HTTP POST request created

Common Problems

  • 404 Not Found
  • API Timeout
  • DNS Resolution Failed
Layer 7: Application
Protocols: HTTP/HTTPS, FTP, SMTP, DNS
Data Unit: Raw Data
Key Devices: Web Browser
Tools: Postman, cURL, Browser Dev Tools
Layer 6: Presentation
Protocols: SSL/TLS, JPEG, ASCII, MIME
Data Unit: Formatted & Encrypted Data
Key Devices: SSL/TLS Processor
Tools: OpenSSL, Character Encoding Tools
Layer 5: Session
Protocols: NetBIOS, RPC, PPTP
Data Unit: Session Data
Key Devices: Session Manager
Tools: Wireshark Session Analysis, Session Trackers
Layer 4: Transport
Protocols: TCP, UDP, SCTP
Data Unit: Segments
Key Devices: Load Balancer
Tools: netstat, tcpdump, Port Scanners
Layer 3: Network
Protocols: IPv4, IPv6, ICMP
Data Unit: Packets
Key Devices: Router
Tools: ping, traceroute, route
Layer 2: Data Link
Protocols: Ethernet, MAC, PPP
Data Unit: Frames
Key Devices: Network Card
Tools: ifconfig/ipconfig, arp
Layer 1: Physical
Protocols: Ethernet Standards, USB, Bluetooth
Data Unit: Bits
Key Devices: Cable
Tools: Cable Tester, Multimeter