watching video helped me; search youtube
than use online subnet calc to verify your answers.
there are several websites to practice subetting.
and my favorite is
Simply learn your sixteen times table until you know it perfectly.
One thing you need to be careful of is to not learn from too many different sources. Pick one method that you like and stick to it. It can get really confusing if you don't commit one method to memory.
Once you decide on a method, tons of practice is key.
I perfer going by the 2^ method
i used to ask this question to everybody and a friend of mine said watch jermey ciora CBT and ur done...hmm i thought lets give it a try ...and it was the end of my all subnetting worries...if u work on his subnetting video u will see good result on the same day its **** TRU
Here's how it worked for me.....I was trying to LEARN it, and it was confusing (partly because I was trying to learn from too many different resources). I re-enrolled back in the local Community College which had the Cisco Academy. It was my second time. And I kept trying to "get it." All of a sudden it just clicked and it all became clear. My problem (and my problem why I couldn't "get it" and struggled with Cisco in the past) was I tried to just LEARN what I was doing and I wasn't trying to UNDERSTAND what I was doing. Once I started to focus and UNDERSTAND subnetting, and other parts of CCisco, it all became crystal clear and lots of fun....NOW. Keep going over it over and over and UNDERSTAND what you are learning. If you can't TRULY UNDERSTAND what you are doing , and why, you'll never "get it" until you do.
Yes I agree. You need to understand it and most people look for magic methods to do it without understanding it but if you learn the table above and the powers of two then it is actually easy.
Learn Binary- 1} becuase it harder to learn the cheats than the right way 2} you need to summarize - which if you end up doing a lot of in your career
Memorize powers of 2
add in Josh's 2^ method
I'll put it this way...... i taught our phone guy, who has ZERO IT anything, too subnet, determine valid hosts and subnet in less than an hour using the above
I've never seen the "sixteen times table" but just looking at it confuses me
There is no need to learn binary what so ever. All you need is your powers of two and the sixteen times table. Binary means two and sixteen is two to the power of four. If people do not know the two, four and eight times table they may be a little young for CLN. IP numbers are blocks of 256 so you can identify the summarize 256 by examination. After that you simply identify within which power of two the lower and upper entries lies. Most people do not understand the properties of the number of two and so the binary method is taught endlessly.
I guess @ 36 I'm just old fashion
Well i agree with Conwyn, even i find it simple usng 16 times table :-)
Subneting is something you just have to do. It may seem hard to understand at first. But after some time, you will find the right way. And it will become easy. First learn your 16 times table maybe up to 256.
I write out 8 bits of of binary values 128, 64, 32, 16, 8, 4,2,1. Then circle the network values and draw a line at the subnet boundary. Using this as a visual aid. I can usualy just add things up in my head. Simple example.... 10.10.10.129/25. The 10.10.10 part is easy. Then if i circle the 128 bit and draw a line to the right of the 128 bit, it all makes sense. Every bit to the right of 128 is a host bit.
You really have to be comfortable with binary math. Just do the subnet game for a while.