In a past Cisco CCENT accreditation exam tutorial, all of us brought up broadcasts and even the potential associated with a broadcast thunderstorm. (If you overlooked that one, check out my website’s Courses section. ) Found in today’s tutorial, most of us discuss a number of different common network devices and how they aid to limit broadcast propagation – or in some cases, how they carry out not help!

Found in the “do certainly not help” department, we’ll find hubs and even repeaters. These a couple of devices operate in Layer 1 regarding the OSI one (the Physical layer), and their single purpose is to be able to strengthen the electric powered signals sent above the cable. Indicate have anything to do with switching or routing, and they do not support to limit messages. ( is basically just a repeater with an increase of ports. )

One the other side of the coin end associated with the spectrum, many of us have routers. Routers operate at Layer 3 of the OSI model (the Network layer), and even by default routers do not frontward broadcasts. They can be configured to “translate” certain broadcast types into unicasts, but you’ll understand more about of which within your CCNA studies.

Since routers do not forward shows, there’s a misunderstanding that routers have nothing to carry out with broadcasts. Routers can indeed generate contacts, and they also can accept them – but they will not likely ahead them. That’s a good important distinction.

Involving these two opposites, we find switches. Buttons operate at Layer 2 of the particular OSI model (the Data Link layer), and the arrears behavior of some sort of switch is to accept a transmit and forward it out every some other single port upon that switch apart from the port that will first received the particular broadcast.

If of which sounds like a whole lot of broadcast forwarding, it is! When we offer an 80-port switch and one interface receives a transmit, by default a duplicate of that send out will be forwarded out there the other seventy nine ports. Most likely, not necessarily all of these hosts connected to be able to those switchports want to see that broadcast, and sending unnecessary broadcast benefits in an unnecessary use of system resources, particularly bandwidth.

Luckily for us all, there is a way to be able to configure a Cisco switch to limit which ports get that broadcast, plus we’ll take some sort of look at that method in typically the next installment regarding my Cisco CCENT certification exam article series!

Chris Bryant, CCIE #12933, is usually the owner involving The Bryant Advantage, home of totally free Gresca CCENT Certification and even CCNA Certification Examination tutorials, The supreme CCNA Study Package, and even Ultimate CCNP Analyze Packages.

You may also visit his blog, which often is updated a couple of times daily with brand new Cisco certification content articles, free tutorials, plus daily CCNA / CCNP exam questions!

Visit his blog and sign up for Certification Key, a daily e-zine packed with CCNA, Network+, A+, and even CCNP certification assessment practice questions. The free 7-part program, �How To Pass The CCNA�, is likewise available

Leave a Reply

Your email address will not be published. Required fields are marked *