[b]OSI Help[/b]

Smoothie

Hey All,
Just started to study for my CCNA. I purchased the Sybex book and it goes into great detail on the OSI model. The book almost seems like it is giving too much information. Besides knowing the layers and thier primary function, how indepth do you need to know it?

Thank you in advance![/b]

viper75

Cisco wants you to know the OSI model inside and out!!! I am in the Cisco Academy now and I'm taking my Switching basics final exam tonite . Most of the assestment test ask you at least 5 questions that have to do with the OSI model. One question for example: In what layer do routers operate? Answer: Layer 3 (Network layer) Or what layer do switches operate? Answer: Layer 2 (Data layer). There are more difficult questions, but those are 2 easy questions that I can remember right now. I highly recommend that you learn the OSI model in detail. Good Luck!!!

Wish me luck on my final tonite!!!

Smoothie

Thanks and Good Luck!
Let us know how you made out......

M_Boyd

When I started the Academy Program about 15 weeks ago I asked the same question. I thought cisco where just being a bit pendantic about an out of date network model.

But your understanding of OSI just grows and grows and it helps make things clearer and helps you to understand the roles of the process. Cisco (concluding from what Ive done so far) mainly focuses on the transport layer downwards. Not only that you can understand the DOD TCP/IP model alot easier also as the OSI can be immediately assigned layers from the OSI.

viper75

Cisco (concluding from what Ive done so far) mainly focuses on the transport layer downwards. Not only that you can understand the DOD TCP/IP model alot easier also as the OSI can be immediately assigned layers from the OSI.

You're absolutely right on that ...Cisco likes to be involved more with the lower layers of the OSI model. Transport, Network, Data, and Physical Layers. Of course all seven layers of the OSI model are tested on and all 7 layers are involved with network communications, BUT you will get more questions regarding the lower layers of the OSI model.

dagr8tim

viper75 wrote:

Cisco likes to be involved more with the lower layers of the OSI model. Transport, Network, Data, and Physical Layers. Of course all seven layers of the OSI model are tested on and all 7 layers are involved with network communications, BUT you will get more questions regarding the lower layers of the OSI model.

But if you think about it. Cisco doesn't care where the data came from in the computer. It just wants to get it moved to where it needs to be.

I kinda take the same attitude at work. I do tier 2 tech support. Once I have established that they have a connection and can view webpages, send email, and that sort of stuff, I could care less. They have connectivity.

Sartan

I find the OSI absolutely critical in networking. It's handy to have a troubleshooting guideline, and even more handy to know what level you're working on when you're doing things. I can't really get into specifics, but as you move along through the CCNA you'll definately understand. Just wait until you study layer 4-7 switching and routing!
Did you know Voice over IP is layer 7 switching?

Make a definate effort to learn the OSI. After you get it once it will be so natural to you that you wouldn't think another word about it.