Network Ninja

Working from the my last couple of OSPF posts I am going to try and crystallize some of the material found by working through questions found in Stewart, B,D., Gough, C (2008). CCNP BSCI Official Exam Certification Guide, Fourth Edition. Indianapolis: Cisco Press book.

5. The Metric used by OSPF is cost. How would you change the metric on an interface?

OSPF cost is a 16-bit variable (0 – 65,535) where lower variables are preferred. There are two methods one preferred (at least by me) and one easier.

I prefer the “automatic” method because it is not hard coded into IOS (SET) that means when dynamic changes occur on the network a change is needed inside IOS to change the costs again.

This method is the one where you change the automatic cost calculation equation to take into account faster links by fiddling with the numerator (add a couple of zeros).

Router_2(config-if)#up ospf auto-cost reference-bandwidth [reference-bandwidth]

Second method is more straightforward and directly onto interfaces (hard code a value)

Router_2(config-if)#ip ospf cost [cost]

Resources:

Stewart, B,D., Gough, C (2008). CCNP BSCI Official Exam Certification Guide, Fourth Edition. Indianapolis: Cisco Press.

Notes and Notices: This is a part of my personal BSCI notes and research to assist myself in learning and understanding the concepts and theory for the BSCI exam. I learn by making notes reading and writing things down and wish to file them where I cannot lose them. These notes are not to be seen, judged or mistaken for replacements to Cisco recognized and authorized training which I personally support and attend and suggest you undertake if you are going for the BSCI Certification.