CCNA

Subnet Cheat Sheet

CIDR	Subnet Mask	Host Bits	Hosts
/32	255.255.255.255	0	1 (Host)
/31	255.255.255.254	1	0 (P2P)
/30	255.255.255.252	2	2
/29	255.255.255.248	3	6
/28	255.255.255.240	4	14
/27	255.255.255.224	5	30
/26	255.255.255.192	6	62
/25	255.255.255.128	7	126
/24	255.255.255.0	8	254
/23	255.255.254.0	9	510
/22	255.255.252.0	10	1,022
/21	255.255.248.0	11	2,046
/20	255.255.240.0	12	4,094
/19	255.255.224.0	13	8,190
/18	255.255.192.0	14	16,382
/17	255.255.128.0	15	32,766
/16	255.255.0.0	16	65,534
/15	255.254.0.0	17	131,070
/14	255.252.0.0	18	262,142
/13	255.248.0.0	19	524,286
/12	255.240.0.0	20	1,048,574
/11	255.224.0.0	21	2,097,150
/10	255.192.0.0	22	4,194,302
/9	255.128.0.0	23	8,388,606
/8	255.0.0.0	24	16,777,214