ZyWALL 2 and ZyWALL 2WE

Chart K-13 Class B Subnet Planning

NO. “BORROWED” HOST BITS

SUBNET MASK

NO. SUBNETS

NO. HOSTS PER SUBNET

 

 

 

 

4

255.255.240.0 (/20)

16

4094

 

 

 

 

5

255.255.248.0 (/21)

32

2046

 

 

 

 

6

255.255.252.0 (/22)

64

1022

 

 

 

 

7

255.255.254.0 (/23)

128

510

 

 

 

 

8

255.255.255.0 (/24)

256

254

 

 

 

 

9

255.255.255.128

512

126

 

(/25)

 

 

10

255.255.255.192

1024

62

 

(/26)

 

 

11

255.255.255.224

2048

30

 

(/27)

 

 

 

 

 

 

12

255.255.255.240

4096

14

 

(/28)

 

 

 

 

 

 

13

255.255.255.248

8192

6

 

(/29)

 

 

14

255.255.255.252

16384

2

 

(/30)

 

 

15

255.255.255.254

32768

1

 

(/31)

 

 

 

 

 

 

52

IP Subnetting