ZyXEL Communications ZyXEL Vantage VSG-1000 User Manual
Page 124
VSG-1000 Vantage Service Gateway
R
IP Subnetting
Chart 15 Eight Subnets
SUBNET SUBNET
ADDRESS
FIRST
ADDRESS
LAST ADDRESS
BROADCAST
ADDRESS
4 96 97 126 127
5 128 129 158
159
6 160 161 190
191
7 192 193 222
223
8 224 223 254
255
The following table is a summary for class “C” subnet planning.
Chart 16 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 5) available for subnetting.
The following table is a summary for class “B” subnet planning.
Chart 17 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
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
(/25)
512 126
10 255.255.255.192
(/26)
1024 62
11 255.255.255.224
(/27)
2048 30