OPS 301 Class 01 - MackD51/CyberReadingNotes GitHub Wiki

Reading Notes For 301 Class 1 Layers of OSI Model & Wireshark

  • Layers for an OSI Model

  • Physical Layer The physical layer deals with the transmission of raw unstructured data bits over a physical medium, such as copper wires or fiber optics. It focuses on transmitting data's electrical, mechanical, and procedural aspects.

  • Data Link Layer The data link layer provides error-free transmission of data frames between two directly connected nodes over a physical layer. It ensures reliable and synchronized communication by detecting and correcting errors that may occur at the physical layer.

  • Network Layer The network layer handles data packets' logical addressing and routing across multiple networks. It determines the optimal path for data to travel from the source to the destination, considering factors like network congestion, addressing, and packet sequencing.

  • Transport Layer The transport layer ensures reliable and transparent end-to-end data delivery between hosts. It breaks down large data chunks into smaller segments, manages data flow, and provides error recovery and retransmission capabilities.

  • Session Layer The session layer establishes, manages, and terminates connections between applications. It provides session synchronization, checkpointing, and recovery services, allowing for organized and efficient communication between applications.

  • Presentation Layer The presentation layer is responsible for data formatting, compression, encryption, and decryption. It ensures that data exchanged between applications is presented in a format that both can understand, regardless of their internal representations.

  • Application Layer The application layer interacts directly with end-users and provides network services for applications. It includes protocols for various functions like email, file transfer, remote access, and web browsing, allowing users to access and utilize network resources.

What Is Wireshark and How To Use It?

  • Network packet capture tool.
  • This tool allows the user to break down a network and be able to scrutinize every aspect to identify and study issues.
  • Also used for network troubleshooting and by cyber security to trace network traffic.
  • It has three functions- Packet capture, Filtering, and Visualization

References

  1. https://www.geeksforgeeks.org/layers-of-osi-model/
  2. https://www.comptia.org/content/articles/what-is-wireshark-and-how-to-use-it

What I Would Like To Know More About

  • Would you use a similar tool if the network was being utilized by someone with a VPN