Class A Subnet Masks Flashcards
255.0.0.0
Class A default network mask
8 network bits, 24 host bits (none borrowed for submitting)
1 network, 16,777,214 hosts
255.128.0.0
9 network bits (1 bit borrowed), 23 host bits
2 subnets, 8,388,606 hosts per subnet
255.192.0.0
10 network bits (2 borrowed), 22 host bits
4 subnets, 4,194,302 hosts per subnet
255.224.0.0
11 network bits (3 borrowed), 21 host bits
8 subnets, 2,097,150 hosts per subnet
255.240.0.0
12 network bits (4 borrowed), 20 host bits
16 subnets, 1,048,574 hosts per subnet
255.248.0.0
13 network bits (5 borrowed), 19 host bits
32 subnets, 524,286 hosts per subnet
255.252.0.0
14 network bits (6 borrowed), 18 host bits
64 subnets, 262,142 hosts per subnet
255.254.0.0
15 network bits (7 borrowed), 17 host bits
128 networks, 131,070 hosts per subnet
255.255.0.0
Class A
16 network bits (8 borrowed), 16 host bits
256 subnets, 65,534 hosts per subnet
255.255.128.0
Class A
17 network bits (9 borrowed), 15 host bits
512 subnets, 16,382 hosts per subnet
255.255.192.0
Class A
18 network bits (10 borrowed), 14 host bits
1,024 subnets, 16,382 hosts per subnet
255.255.224.0
Class A
19 network bits (11 borrowed), 13 host bits
2,048 subnets, 8,190 hosts per subnet
255.255.240.0
Class A
20 network bits (12 borrowed), 12 host bits
4,096 subnets, 4,094 hosts per subnet
255.255.248.0
Class A
21 network bits (13 borrowed), 11 host bits
8,192 subnets, 2,046 hosts per subnet
255.255.252.0
Class A
22 network bits (14 borrowed), 10 host bits
16,384 subnets, 1,022 hosts per subnet
255.255.254.0
Class A
23 network bits (15 borrowed), 9 host bits
32,768 subnets, 510 hosts per subnet
255.255.255.0
Class A
24 network bits (16 borrowed), 8 host bits
65,536 subnets, 254 hosts per subnet
255.255.255.128
Class A
25 network bits (17 borrowed), 7 host bits
131,072 subnets, 126 hosts per subnet
255.255.255.192
Class A
26 network bits (18 borrowed), 6 host bits
262,144 subnets, 62 hosts per subnet
255.255.255.224
Class A
27 network bits (19 borrowed), 5 host bits
524,288 subnets, 30 hosts per subnet
255.255.255.240
Class A
28 network bits (20 borrowed), 4 host bits
1,048,576 subnets, 14 hosts per subnet
255.255.255.248
Class A
29 network bits (21 borrowed), 3 host bits
2,097,152 subnets, 6 hosts per subnet
255.255.255.252
Class A
30 network bits (22 borrowed), 2 host bits
4,194,302 subnets, 2 hosts per subnet
255.255.255.254
Class A
31 network bits (23 borrowed), 1 host bit
8,388,608 subnets, 2 IP addresses; this is described in RFC 3021 as a point-to-point link. Both IP addresses are used as hosts, and broadcasts are limited.
