CCNA Notes
Introduction
Cisco offers two options for obtaining the CCNA certification:
 

Pass Exam 640-802 OR Pass Exam 640-822 AND Exam 640-816

While you can use these notes to prepare for either exam, the notes are geared towards passing the single exam. I recommend you study all of the material and take the single exam option rather than taking two exams. Cisco Device Icons  The following table lists the specific icons Cisco uses to represent network devices and connections. Represents

Icon

Hub

Bridge

Switch

Router

Access point

Network cloud

Ethernet connection

Serial Line connection

Wireless connection

Virtual Circuit

The OSI Model
As you study this section, answer the following questions:
     

What is the OSI model and why is it important in understanding networking? How does the third OSI model layer relate to administering routers? Which OSI model layer is concerned with MAC addresses? What protocols correspond to the Presentation and Session layers? What is the difference between the TCP and UDP protocols? What is the EIA/TIA 232 protocol concerned with?

This section covers the following exam objectives:
  

103. Use the OSI and TCP/IP models and their associated protocols to explain how data flows in a network 105. Describe the purpose and basic operation of the protocols in the OSI and TCP models 110. Identify and correct common network problems at layers 1, 2, 3 and 7 using a layered model approach

OSI Model Facts The OSI model classifies and organizes the tasks that hosts perform to prepare data for transport across the network. You should be familiar with the OSI model because it is the most widely used method for understanding and talking about network communications. However, remember that it is only a theoretical model that defines standards for programmers and network