Шпаргалка по сетевым маскам

Свойства сетей класса A, B и C.

 Class AClass BClass C
Первый октет1-126128-191192–223
Доступные сети1.0.0.0–126.0.0.0128.0.0.0–191.255.0.0192.0.0.0–223.255.255.0
Всего сетей в классе27 – 2 = 126214 = 16,384221 = 2,097,152
Хостов в сети224 – 2216 – 228 – 2
Битов в сети81624
Битов в хосте24168
Маска по умолчанию255.0.0.0255.255.0.0255.255.255.0

Диапазон приватных IP адресов

RFC1918 nameIP address rangeNumber of addressesLargest CIDR block (subnet mask)Host ID sizeMask bits
24-bit block10.0.0.0 – 10.255.255.2551677721610.0.0.0/8 (255.0.0.0)24 bits8 bits
20-bit block172.16.0.0 – 172.31.255.2551048576172.16.0.0/12 (255.240.0.0)20 bits12 bits
16-bit block192.168.0.0 – 192.168.255.25565536192.168.0.0/16 (255.255.0.0)16 bits16 bits

Различные значения сетевых масок

Binary Mask OctetsDecimal EquivalentNumber of Binary 1s
0000000000
10000001281
110000001922
111000002243
111100002404
111110002485
111111002526
111111102547
111111112558

Class A

Network BitsSubnet MaskNumber of SubnetsNumber of Hosts
/8255.0.0.0016777214
/9255.128.0.02 (0)8388606
/10255.192.0.04 (2)4194302
/11255.224.0.08 (6)2097150
/12255.240.0.016 (14)1048574
/13255.248.0.032 (30)524286
/14255.252.0.064 (62)262142
/15255.254.0.0128 (126)131070
/16255.255.0.0256 (254)65534
/17255.255.128.0512 (510)32766
/18255.255.192.01024 (1022)16382
/19255.255.224.02048 (2046)8190
/20255.255.240.04096 (4094)4094
/21255.255.248.08192 (8190)2046
/22255.255.252.016384 (16382)1022
/23255.255.254.032768 (32766)510
/24255.255.255.065536 (65534)254
/25255.255.255.128131072 (131070)126
/26255.255.255.192262144 (262142)62
/27255.255.255.224524288 (524286)30
/28255.255.255.2401048576 (1048574)14
/29255.255.255.2482097152 (2097150)6
/30255.255.255.2524194304 (4194302)2

Class B

Network BitsSubnet MaskNumber of SubnetsNumber of Hosts
/16255.255.0.0065534
/17255.255.128.02 (0)32766
/18255.255.192.04 (2)16382
/19255.255.224.08 (6)8190
/20255.255.240.016 (14)4094
/21255.255.248.032 (30)2046
/22255.255.252.064 (62)1022
/23255.255.254.0128 (126)510
/24255.255.255.0256 (254)254
/25255.255.255.128512 (510)126
/26255.255.255.1921024 (1022)62
/27255.255.255.2242048 (2046)30
/28255.255.255.2404096 (4094)14
/29255.255.255.2488192 (8190)6
/30255.255.255.25216384 (16382)2

Class C

Network BitsSubnet MaskNumber of SubnetsNumber of Hosts
/24255.255.255.00254
/25255.255.255.1282 (0)126
/26255.255.255.1924 (2)62
/27255.255.255.2248 (6)30
/28255.255.255.24016 (14)14
/29255.255.255.24832 (30)6
/30255.255.255.25264 (62)2

Class D

CIDR BlockSupernet MaskNumber of Class C AddressesNumber of Hosts
/14255.252.0.01024262144
/15255.254.0.0512131072
/16255.255.0.025665536
/17255.255.128.012832768
/18255.255.192.06416384
/19255.255.224.0328192
/20255.255.240.0164096
/21255.255.248.082048
/22255.255.252.041024
/23255.255.254.02512