Book Review: CCIE Routing and Switching Certification Guide 4th Edition

As part of studying for the CCIE R&S Written exam I got myself a copy of the CCIE Routing and Switching Certification Guide 4th edition by Wendell Odom, Rus Healy, and Denise Donahue.  This is the newly revised version for the CCIE R&S v4 written exam that came out very shortly after the new version of the exams did, and it's also the updated version of a book that's been around for a very long time.

I used this book extensively in my written exam preparation, and now that that piece is completed, I wanted to briefly reflect on this text and the role it played.  It was certainly a love/hate experience, and if you are considering this text in your own studies then you should definitely be aware of a few things prior to purchasing this book. 

Retro Post: Session Initiation Protocol: Evolution in IP Telephony Signalling

Since I'm into retro posts this morning, here's another oldie circa 2005.  This was an assignment from when I was in school.  Looking back it's not very useful...  But hey, what the heck, right?

Retro Post: An Introduction to Subnetting

Back in about 2003/4 I wrote a tutorial on subnetting.  I posted it up on a couple forums that I frequented at the time and then forgot about it.  I came across it about again about a year ago, and then today I actually dug it up to reference it in a post I was making.

Since its mine, I decided that I would post it up here now.  I think it's fun to go back to when I was getting my start in Networking and see some of the sorts of things I wrote back then.  So without further ado, get into the time machine and enjoy this old, very basic tutorial.

Written down. Lab to go.

I passed the 350-001 CCIE Routing and Switching Written test today.

Onwards to the lab!

The Mess that is QoS in Layer 2

Since I looked at QoS Classification and Marking in the IP Header I figure I might as well finish it off and go over the same topic at Layer 2.  I kept the title, but in reality it's not that bad here.  There's a lot more consistency between the various Layer 2 technologies and things seem to translate pretty well.  The only real challenge comes into play when you need to start translating a Layer 2 marking to a Layer 3 marking, and vice versa.  I'll get to that in a bit, but first lets look at what we have to work with.

The Mess that is QoS in the IP Header

If there's a group of people out there that should be drug out into the street and shot it's the jackasses that designed QoS classification and marking in the IP . More specifically, the jackasses that decided we needed multiple definitions of the same bits and different bits at different layers. I sometimes wonder if the only reason that QoS classification and marking is this way is so that vendors, like Cisco, can test you on it.

At any rate, things are the way they are and we must learn it.