Master CCNA

How to Master CCNA Ebook

 

 Start your networking career and Master CCNA

Master CCNP SWITCH

How to master CCNP SWITCH ebook

 

 Become a switching guru and Master CCNP SWITCH

Master CCNP ROUTE

How to master CCNP ROUTE Ebook

 

 Dominate routing protocols and Master CCNP ROUTE

Master CCNP TSHOOT

How to Master CCNP TSHOOT

 

 Complete your CCNP R&S journey and Master CCNP TSHOOT

Print

OSPF Auto Cost Reference Bandwidth

Written by Rene Molenaar on . Posted in OSPF

Scenario:

The new muppet movie is almost finished. All the actresses prefer to have a dedicated internet connection in their trailers at the movie park. You configure a couple of routers with Gigabit and FastEthernet interfaces. Unfortunately OSPF doesn't seem to make a difference between FastEthernet and Gigabit links. It's up to you to make the changes so it does see a difference...

Goal:

  • All IP addresses have been preconfigured for you.
  • Configure OSPF on all routers. Achieve full connectivity.
  • Without changing the OSPF cost on each interface, ensure OSPF will make the best use of the Gigabit interfaces. In the future you will also add some ten Gigabit links so this is something to be aware of.

It took me 1000s of hours reading books and doing labs, making mistakes over and over again until I mastered all the protocols for CCNA.

Would you like to be a master of networking too? In a short time without having to read 900 page books or google the answers to your questions and browsing through forums?

I collected all my knowledge and created a single ebook for you that has everything you need to know to become a master of CCNA.

You will learn all the secrets about OSPF, path calculation, the SPF algorithm, metrics and more.

Does this sound interesting to you? Take a look here and let me show you how to Master CCNA!

IOS:

c7200-adventerprisek9-mz.124-20.T.bin

Topology:

OSPF Auto-Cost Reference Bandwidth Network Topology

Video Solution:

You need to a flashplayer enabled browser to view this YouTube video

You need to register to download the GNS3 Topology File. (Registration is Free!)

Only registered users can write comments!

Comments (2)

  • avatar
    baloo247
    2011-09-26 12:14:36

    do we simply set the reference bw to 10000 Mbps? this set's it at 10Gbps correct, as the bw is defined as Mbps.

  • avatar
    ReneMolenaar
    2011-09-26 23:04:34

    Yup that's it. By default OSPF will use a 100mbit interface for the reference bandwidth. That means a 100mbit interfaces gets a cost of 1. (100 / 100 = 1).

    You can't have a cost of 0,1 for Gigabit or 0,01 for 10Gigabit. That's why you need to change the reference bandwidth.

    If you get it to 10Gigabit then it'll look like this:

    10Gigabit: Cost 1
    Gigabit: Cost 10
    100Mbit: Cost 100

feedback