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Table Of Contents  The TCP/IP Guide
 9  TCP/IP Lower-Layer (Interface, Internet and Transport) Protocols (OSI Layers 2, 3 and 4)
      9  TCP/IP Internet Layer (OSI Network Layer) Protocols
           9  Internet Protocol (IP/IPv4, IPng/IPv6) and IP-Related Protocols (IP NAT, IPSec, Mobile IP)
                9  Internet Protocol Version 4 (IP, IPv4)
                     9  IP Addressing
                          9  IP Subnet Addressing ("Subnetting") Concepts

Previous Topic/Section
IP Subnet Identifiers, Subnet Addresses and Host Addresses
Previous Page
Pages in Current Topic/Section
1
2
34
Next Page
IP Variable Length Subnet Masking (VLSM)
Next Topic/Section

IP Subnetting Summary Tables For Class A, Class B and Class C Networks
(Page 2 of 4)

Class A


Table 52: Subnetting Summary Table For Class A Networks

# of Subnet ID Bit

# of Host ID Bits

# of Subnets Per Network

# of
Hosts Per Subnet

Subnet Mask

(Binary / Dotted Decimal)

Subnet Mask (Slash/ CIDR Notation)

Subnet Address #N Formula (N=0, 1, … # of Subnets-1)

0 (Default)

24

1

16,277,214

11111111.00000000.0000000.00000000

255.0.0.0

/8

1

23

2

8,388,606

11111111.10000000.0000000.00000000

255.128.0.0

/9

x.N*128.0.0

2

22

4

4,194,302

11111111.11000000.0000000.00000000

255.192.0.0

/10

x.N*64.0.0

3

21

8

2,097,150

11111111.11100000.00000000.00000000

255.224.0.0

/11

x.N*32.0.0

4

20

16

1,048,574

11111111.11110000.00000000.00000000

255.240.0.0

/12

x.N*16.0.0

5

19

32

524,286

11111111.11111000.00000000.00000000

255.248.0.0

/13

x.N*8.0.0

6

18

64

262,142

11111111.11111100.00000000.00000000

255.252.0.0

/14

x.N*4.0.0

7

17

128

131,070

11111111.11111110.00000000.00000000

255.254.0.0

/15

x.N*2.0.0

8

16

256

65,534

11111111.11111111.00000000.00000000

255.255.0.0

/16

x.N.0.0

9

15

512

32,766

11111111.11111111.10000000.00000000

255.255.128.0

/17

x.N/2.

(N%2)*128.0

10

14

1,024

16,382

11111111.11111111.11000000.00000000

255.255.192.0

/18

x.N/4.

(N%4)*64.0

11

13

2,048

8,190

11111111.11111111.11100000.00000000

255.255.224.0

/19

x.N/8.

(N%8)*32.0

12

12

4,096

4,094

11111111.11111111.11110000.00000000

255.255.240.0

/20

x.N/16.

(N%16)*16.0

13

11

8,192

2,046

11111111.11111111.11111000.00000000

255.255.248.0

/21

x.N/32.

(N%32)*8.0

14

10

16,384

1,022

11111111.11111111.11111100.00000000

255.255.252.0

/22

x.N/64.

(N%64)*4.0

15

9

32,768

510

11111111.11111111.11111110.00000000

255.255.254.0

/23

x.N/128.

(N%128)*2.0

16

8

65,536

254

11111111.11111111.11111111.00000000

255.255.255.0

/24

x.N/256.

N%256.0

17

7

131,072

126

11111111.11111111.11111111.10000000

255.255.255.128

/25

x.N/512.

(N/2)%256.

(N%2)*128

18

6

262,144

62

11111111.11111111.11111111.11000000

255.255.255.192

/26

x.N/1024.

(N/4)%256.

(N%4)*64

19

5

524,288

30

11111111.11111111.11111111.11100000

255.255.255.224

/27

x.N/2048.

(N/8)%256.

(N%8)*32

20

4

1,048,576

14

11111111.11111111.11111111.11110000

255.255.255.240

/28

x.N/4096.

(N/16)%256.

(N%16)*16

21

3

2,097,152

6

11111111.11111111.11111111.11111000

255.255.255.248

/29

x.N/8192.

(N/32)%256.

(N%32)*8

22

2

4,194,304

2

11111111.11111111.11111111.11111100

255.255.255.252

/30

x.N/16384.

(N/64)%256.

(N%64)*4


Previous Topic/Section
IP Subnet Identifiers, Subnet Addresses and Host Addresses
Previous Page
Pages in Current Topic/Section
1
2
34
Next Page
IP Variable Length Subnet Masking (VLSM)
Next Topic/Section

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