ZyWALL 2 and ZyWALL 2WE

 

 

 

Chart K-11 Eight Subnets

 

 

 

 

 

 

 

 

 

 

 

 

SUBNET

SUBNET ADDRESS

FIRST ADDRESS

LAST ADDRESS

 

BROADCAST ADDRESS

 

 

 

 

 

 

 

 

 

 

8

224

223

254

 

255

 

 

 

 

 

 

 

 

 

The following table is a summary for class “C” subnet planning.

Chart K-12 Class C Subnet Planning

NO. “BORROWED” HOST BITS

SUBNET MASK

NO. SUBNETS

NO. HOSTS PER SUBNET

 

 

 

 

1

255.255.255.128 (/25)

2

126

 

 

 

 

2

255.255.255.192 (/26)

4

62

 

 

 

 

3

255.255.255.224 (/27)

8

30

 

 

 

 

4

255.255.255.240 (/28)

16

14

 

 

 

 

5

255.255.255.248 (/29)

32

6

 

 

 

 

6

255.255.255.252 (/30)

64

2

 

 

 

 

7

255.255.255.254 (/31)

128

1

 

 

 

 

Subnetting With Class A and Class B Networks.

For class “A” and class “B” addresses the subnet mask also determines which bits are part of the network number and which are part of the host ID.

A class “B” address has two host ID octets available for subnetting and a class “A” address has three host ID octets (see Chart K-1) available for subnetting.

The following table is a summary for class “B” subnet planning.

Chart K-13 Class B Subnet Planning

NO. “BORROWED” HOST BITS

SUBNET MASK

NO. SUBNETS

NO. HOSTS PER SUBNET

 

 

 

 

1

255.255.128.0 (/17)

2

32766

 

 

 

 

2

255.255.192.0 (/18)

4

16382

 

 

 

 

3

255.255.224.0 (/19)

8

8190

 

 

 

 

IP Subnetting

51