Multiarea OSPF for the CCNA

Multiarea OSPF Overview

Multiarea OSPF is used in large or enterprise networks where there are so many routers that having every router communicating every link in their link state database with every other router in the network, even when it is a small change becomes taxing on the network. In this type of situation you don’t need every router, lets say there are 30 or more routers, running the shortest path first algorithm if an interface is momentarily shut down.

The solution is to use multi-area OSPF instead of single area OSPF where every network is in Area 0. In multiarea OSPF you still have to have a backbone area named Area 0 but you can add additional networks in other areas. The result is that routers will only share their entire link state databases with routers in there own area and other areas will be configured to receive only summary information from the area. This way, when there is a change in the network the SPF algorithm will only need to run on routers in the effected area.

I created a packet tracer lab activity that goes with a video tutorial series. Watch all of the videos in-order below, while you follow along with the downloadable packet activity here: multi-area-ospf-begin

Multiarea OSPF Video Tutorial

 

 

Author: Dan

Dan teaches computer networking and security classes at Central Oregon Community College.

2 thoughts on “Multiarea OSPF for the CCNA”

  1. My name is John, I’m a 75yr old past “techie”, I worked for Unisys for 30yrs, as a systems engineer (repairing Main Frames), became a OS person, learned mostly self taught, programming (I refer to myself as a thief rather than a programmer), I never saw a subroutine I didn’t put to some other useful purpose. But with HW & SW background I never failed to fix it or tell some what they needed to get it fixed. I retired in 2000 and now I just support My local FD and Emgcy Ops Center, as a volunteer.. I am just getting into Cisco Equipment, as the on Site “Guru”, your videos made VLAN’s understandable, and makes me want more info.. I LOVE what Packet Tracer does, and must add it to my knowledge base, BUT as near as I can tell I need to go back to some school to play with it…. Is there a FREE or ALMOST Free way to Play, I’m too old to need a CCNA Cert., but not too old to add to my brain, (already Lost lots. too many…

    1. Hi John, If you go to the http://netacad.com website you can register yourself an account, and then self enroll in some free classes. Once you are logged in I believe you will be able to download Packet Tracer. Also go to your nearest community college and sign up for a Cisco CCNA Routing and Switching course. You can usually sign up for classes with a credit or no credit option. Some schools even offer online classes in Cisco Routing and Switching.

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