How much do I have to memorize

AndreL

Below are the powers of 2 ... 0-32 CCNA exam, how many do we have to know cause I read some where they mostly the exam test you on class C and B subnets but what is it really ... Cause I've already have 0-15 memorized should I go further ?
0
1
2
4
8
16
32
64
128
256
512
1,024
2,048
4,096
8,192
16,384
32,768
65,536
131,072
262,144
524,288
1,048,576
2,097,152
4,194,304
8,388,608
16,777,216
33,554,432
67,108,864
134,217,728
268,435,456
536,870,912
1,073,741,824
2,147,483,648
4,294,967,296

ciscoman2012

I would memorize 0-19 but you will probably only use 0-16.

Todd Burrell

I have simply memorized a few of the main subnet numbers (related to powers of 2), and then I can figure out the other ones. I know that /24 gives 256 addresses (or 254 if you take away the network and b'cast). I also know that /28 gives 16 and /20 gives 4096. Once you know these you can figure out the other subnets.

Same with powers of 2 - just memorize a few and you can quickly figure out the others. I know by heart 2^4=16, 2^8=256 and 2^12=4096 and 2^16 = 65536. From these 4 basic numbers I can quickly find the others. So there is no need to try and memorize every power from 0 through 16 - just learn a few...

cyberguypr

Don't overthink it. Just memorize a few as Todd Burell said. In my case I used similar numbers as a reference point and then proceeded to half or double as required: 2^6=64, 2^10=1024.