I had some requests to provide my take on the OSI model separately from the presentation I made at PwnSchool, so here you go… the most comprehensive, authoritative version of the OSI model ever presented.
The OSI Model – Pro Edition
Introduction to Hardware Protocols
As you begin diving into hardware hacking and reading printed circuit boards (PCB) you will likely come across several common protocols. This article isn’t intended to be an exhaustive list of content, but rather a quick guide to identifying which protocols are commonly used, what they require, and what common tools will let you interface with them. I’ll be covering the following protocols in this article:
- RS-232
- USB
- I2C
- SPI
- JTAG
- UART
- USART
Protocol Deep Dive: ARP
Overview
The Address Resolution Protocol (ARP) allows for conversion from a network layer address to a hardware layer address (e.g. from the IP address to the MAC address). It is defined by RFC 826, and is a layer 2 protocol in the OSI model. For simplicity, this article will refer to IP address resolutions in examples.
Prerequisites
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- Two systems that each know their own IP address and MAC address
- A usable network layer path between the two systems
- The sending system must know the IP address of the destination system
Hermit's Cave 