IP Address Class Network and Host Capacities
| IP Address Class | Total # Of Bits For
Network ID / Host ID |
First Octet of IP Address | # Of Network ID Bits Used
To Identify Class |
Usable # Of Network ID
Bits |
Number of Possible Network
IDs |
# Of Host IDs Per Network
ID |
|
Class A |
8 / 24 |
0xxx xxxx |
1 | 8-1 = 7 | 27-2 = 126 |
224-2 = 16,277,214 |
|
Class B |
16 /
16 |
10xx xxxx |
2 | 16-2
= 14 |
214
= 16,384 |
216-2 = 65,534 |
|
Class C |
24 /
8 |
110x xxxx |
3 | 24-3
= 21 |
221
= 2,097,152 |
28-2
= 254 |
- Se o 1º bit é um “0”, trata-se de um endereço Classe A
- Se o 2º bit é um “0”, trata-se de um endereço Classe B
- Se o 3º bit é um “0”, trata-se de um endereço Classe C
- Se o 4º bit é um “0”, trata-se de um endereço Classe D, (metade do restante, ou um décima sexta do espaço de endereço.) Se for um “1”, é um endereço da classe E. (a outra metade, um décima sexta.)
| IP Address Class | First Octet of IP Address |
Address Lowest Value of First Octet (binary) |
Highest Value of First
Octet (binary) |
Range of First Octet
Values (decimal) |
Octets in Network ID /
Host ID |
Theoretical IP Address
Range |
|
Class A |
0xxx xxxx |
0000 0001 |
0111 1110 |
1 to
126 |
1 / 3 |
1.0.0.0 to 126.255.255.255 |
|
Class B |
10xx xxxx |
1000 0000 |
1011 1111 |
128
to 191 |
2 / 2 |
128.0.0.0 to 191.255.255.255 |
|
Class C |
110x xxxx |
1100 0000 |
1101 1111 |
192
to 223 |
3 / 1 |
192.0.0.0 to 223.255.255.255 |
|
Class E |
1110 xxxx |
1110 0000 |
1110 1111 |
224
to 239 |
– |
224.0.0.0 to 239.255.255.255 |
|
Class D |
1111 xxxx |
1111 0000 |
1111 1111 |
240
to 255 |
– |
240.0.0.0 to 255.255.255.255 |
IP Address Classes and Class Characteristics and Uses
| IP Address Class | Fraction of Total IP
Address Space |
Number Of Network ID Bits | Number Of Host ID Bits | Intended Use |
| Class A | 1/2 | 8 | 24 | Unicast addressing for
very large organizations with hundreds of thousands or millions of hosts to connect to the Internet. |
| Class
B |
1/4 | 16 | 16 | Unicast addressing for
medium-to-large organizations with many hundreds to thousands of hosts to connect to the Internet. |
| Class
C |
1/8 | 24 | 8 | Unicast addressing for
smaller organizations with no more than about 250 hosts to connect to the Internet. |
| Class
D |
1/16 | n/a | n/a | IP multicasting. |
| Class
E |
1/16 | n/a | n/a | Reserved for “experimental use�. |
mais info aqui
Home