Subneting ?

themagicone

I thought I got the whole thing down till now... (it could be labsim, I've found many errors with their CCNA training)

If I have say a /22 or /23 network, what is the proper step for the subnets?
I get 2 for /23 and 4 for /22. That would give me .0.0, .2.0, .4.0 and 0.0, 4.0, 8.0, respectively. Or is that wrong? Labsim is telling me that it is 4 and 8.

I write myself a chart to help
Bit 1 1 1 1 1 1 1 1
Count Number 128 64 32 16 8 4 2 0
Mask Number 128 192 224 240 248 252 254 255
Host/Net 126 65 30 14 6 2 1 0
Subnets 2 4 8 16 32 64 128 192

Sorry, kinda of hard to put it in here.

So going by that chart a /23 would be in the 2nd to last column or 2 count.

Am I way off?

Jollycork

here's a link:

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


it's a really good writeup for subnetting.

here's an except from that subnetting writeup:

Just memorize how many items you get for each number of bits (subtract two for hosts)

000000000001 = 2 (1)
000000000011 = 4 (2)
000000000111 = 8 (3)
000000001111 = 16 (4)
000000011111 = 32 (5)
000000111111 = 64 (6)
000001111111 = 128 (7)
000011111111 = 256 (8 )
000111111111 = 512 (9)
001111111111 = 1024 (10)
011111111111 = 2048 (11)
111111111111 = 4096 (12)