ZyXEL Communications ZyXEL ZyWALL 2WE - Manual (Page 383)

ZyWALL 2 and ZyWALL 2WE
IP Subnetting 51
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