Friday, June 27, 2014

The Networking Basics You Need to Know in Order to Pass the CCENT Exam – Part 1

I'm falling a little behind in my posts. I am still working on Part 3 of the "How to use your cheet-sheat series", but I will get back to it soon, I promise. I will be away at a conference next week, but I will try to publish the article before I leave. Today I have the first installment of a two-part series on the fundamentals of networking that are necessary to know in order to pass the CCENT exam. By no means is it conclusive, but it's a foundation that you need to build upon.

My favorite part about being a teacher is helping students find jobs once they complete their degree.  When I can help a student find a job it makes me feel like I’ve made a difference in their lives.  One way I can help them, besides the normal classroom education that I’m paid to deliver, is to help them to get professionally certified so they gain that extra edge in the job market.
Since I teach computer networking, the Cisco Certified Entry Networking Technician (CCENT) certification is the entry-level cert that I encourage students to obtain.  That being said, here are some of the basic skills and the general knowledge that a student needs to pass the CCENT exam:

1. Basic Device Configuration of Switches, Routers and hosts
A student should be able configure these devices so that they provide end-to-end connectivity in a small network. This includes being able to configure:
  • Device hostnames in order to differentiate one device from another
  • IP addressing on LAN and WAN interfaces (including descriptions)
  • Basic security (passwords and encryption) on all interfaces and the console port
  • A routing protocol and static routes
  • VLANs and trunking
More than likely you will need to display these skills within a simulation question, as well as 8-10 regular questions.

2. Testing End-to-End Connectivity and Verifying a Hosts IP Address

Anyone who’s pursuing there CCENT certification should be able to use connectivity commands like ping and traceroute as well as ipconfig, which is used to check the IP address of the host, and so much more.
3. Effectively Use the Top 4-8 Show Commands for Verification and Troubleshooting

I find that troubleshooting is the hardest thing to teach. Of course, practice is the key to mastering the art of troubleshooting, and knowing which Cisco IOS show commands to use is a good start. Here are the ones I feel you must know:
show running-configuration – The output of this command yields a lot of information to verify and troubleshoot your basic configuration and more.  It will provide you with the most bang for your buck when it comes to investigating how a router and switch are configured.

show ip interface brief - The output of this command will display the state of your interfaces along with the interface address. Simply put, if your interfaces are down, end-to-end connectivity is not happening. Note: there are several other “show interface” commands that will provide more information, however this is the easiest one to interpret, and most times you will find the information that you need. 
show ip route –If the two previous commands fail to provide you with enough information to solve the problem, this command could do the trick, however, it is the hardest of the three to interpret. Basically the output will show you the networks you’re able to reach and how to reach them. However, there’s a lot more to it. By the way, the first two commands can be run both on routers and switches. You would run this command only on the router.

show mac-address-table – This command is similar to the previous command, accept it’s for switches. The output displays the mac address of each device connected to the switch, and the port where each device is connected. 
show vlan  – VLANs play a huge role in today’s networks. This command will allow you to keep track of the VLANs that are configured on a switch, but which ports belong to which VLAN. This comes in handy if connectivity on a switch is not working like you think it should.

These last two commands are for the switch only.

In Part 2, I will look at the following three basic skills:
  1. Resolve an IP Address – Find the Network, Broadcast, First and Last Host, and Next Network Addresses
  2. Understand Switching and Routing Decisions
  3. Know the Characteristics of the Transport, Network, and Data-Link Layers of the OSI Model
Your comments are always welcome.

-Jim Stranz (revised 6/27/2014)

1 comment:

  1. Thanks Jim nice review! More about MAC addresses and how they are processed end to end maybe helpful for some of us.....

    Maybe how IP and MAC addresses change or do not through the path?

    ReplyDelete