CIDR - VLSM - Cheet sheet

VLSM - CIDR - Cheet sheet

VLSM - Variable-length subnet mask
CIDR - Classless Inter-Domain Routing

CIDR	Mask	Block
/9 /17 /25	.128	128
/10 /18 /26	.192	64
/11 /19 /27	.224	32
/12 /20 /28	.240	16
/13 /21 /29	.248	8
/14 /22 /30	.252	4
/15 /23 /31	.254	2

2^x
11	2048	18	262144
12	4096	19	524288
13	8192	20	1048576
14	16384	21	2097152
15	32768	22	4194304
16	65536	23	8388608
17	131072	24	16777216