Subnetting

OmniMan

I'm having difficulty understanding this concept. How much of it is on the exam?

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Comments

jamthat

I seem to recall only running into very basic problems, but every test is different.

You'll have to understand subnetting if you're planning on moving onto the CCNA afterwards. If so, it might be beneficial to take some extra time now to fully grasp it. You'll feel much more prepared when starting on the Cisco certs!

Baack

I would say sub-netting is very important to know
I studied it like crazy for the net+ exam
I had maybe a couple questions, that were pretty easy
I would look into professor Messer videos on line, they are free and may be of help

Hatch1921

http://www.techexams.net/forums/ccna-ccent/38772-subnetting-made-easy.html

Give it a shot.... and yes I agree with Jamthat.... subnetting is very important to understand if you are thinking about pursing your CCNA.

Have a look at Dan's courses on Youtube.... https://www.youtube.com/user/danscourses/videos?flow=grid&view=1

Hope this helps.

Hatch

Tooms

Not to be too direct, but subneting is critical to administering networks period whether you get a cert or not. I would definitely recommend you consider it very important. Every network test I've taken has had subneting on it in various forms.

Look around online for an easy way to right down a subnet listing for different sizes. There are lots of tricks to making one on paper (which you can use during a test).

Quick and dirty is that in order for a device on one subnet to talk to a device on another subnet you need to go through a router or some sort of layer 3 interface. Devices on the same subnet can talk to each other layer 2 without a router. Subnet mask determines how many hosts are on a subnet. Most used one is a /25 or 255.255.255.0 - a /22 is a larger set of hosts. A /28 would be a smaller set of hosts.

In routing, always remember that a route for a smaller (more specific) subnet will trump a router for a larger subnet that encompasses the smaller subnet. This is regardless of the administrative distance on the routing protocol.

After you confuse yourself with IPv4 subnets, feel free to confuse yourself more with IPv6 subnets.

DDWingate

If you want to understand the concept behind subnetting, here it is:

Subnet masks decide which part of your IP address is for the network ID, and which part is for the host.

For example, if my IP address was 10.1.1.1 with a 255.0.0.0 subnet mask, my network ID would be 10 and my host ID would be 1.1.1, but if my subnet mask was 255.255.0.0 then my network ID would be 10.1 and my host ID would be 1.1

-This act of watermarking an IP address with a subnet mask is called 'subnetting'

That's all there is to the concept of subnetting

cesar424

I dont know if this will help you, but it helps me. Made this during one of my classes.

Net+ Notes.jpg

Darril

I'm echoing what some of the other people are saying, but subnetting is important - both for on the job and for other certs. You probably won't get any deep subnetting questions on the Network+ exam, but I remember a recent thread on the Security+ forum where an individual didn't understand subnetting which caused additional confusion with one of the performance based questions.

People have given you several resources and it's worth your time.

Also, in my experience, people seem to grasp subnetting after trying to learn it from two or more sources. The first attempt is difficult and when they use a different resource, something clicks.

newt.chapman

Darril wrote: »

Also, in my experience, people seem to grasp subnetting after trying to learn it from two or more sources. The first attempt is difficult and when they use a different resource, something clicks.

This definitely rings true for me. I was having a lot of difficulty learning it at first using just one source. So I let the information settle for a night and went to a different source the next morning and it all just seemed to click!