ZyXEL G-570U User’s Guide
146
Appendix D IP Subnetting
The following table shows the network number and host ID arrangement for classes A, B and
C.
An IP address with host IDs of all zeros is the IP address of the network (192.168.1.0 for
example). An IP address with host IDs of all ones is the broadcast address for that network
(192.168.1.255 for example). Therefore, to determine the total number of hosts allowed in a
network, deduct two as shown next:
• A class C address (1 host octet:
8 host bits) can have 2
8
– 2, or 254 hosts.
• A class B address (2 host octets: 16 host bits) can have 2
16
– 2, or 65534 hosts.
A class A address (3 host octets: 24 host bits) can have 2
24
– 2 hosts, or approximately 16
million hosts.
IP Address Classes and Network ID
The value of the first octet of an IP address determines the class of an address.
• Class A addresses have a
0
in the leftmost bit.
• Class B addresses have a
1
in the leftmost bit and a
0
in the next leftmost bit.
• Class C addresses start with
1 1 0
in the first three leftmost bits.
• Class D addresses begin with
1 1 1 0
. Class D addresses are used for multicasting, which
is used to send information to groups of computers.
• There is also a class E. It is reserved for future use.
The following table shows the allowed ranges for the first octet of each class. This range
determines the number of subnets you can have in a network.
Table 39
Classes of IP Addresses
IP ADDRESS
OCTET 1
OCTET 2
OCTET 3
OCTET 4
Class A
Network number
Host ID
Host ID
Host ID
Class B
Network number Network number
Host ID
Host ID
Class C
Network number Network number
Network number
Host ID
Table 40
Allowed IP Address Range By Class
CLASS
ALLOWED RANGE OF FIRST OCTET (BINARY)
ALLOWED RANGE OF FIRST
OCTET (DECIMAL)
Class A
0
0000000 to
0
1111111
0 to 127
Class B
10
000000 to
10
111111
128 to 191
Class C
110
00000 to
110
11111
192 to 223
Class D
1110
0000 to
1110
1111
224 to 239
Class E
(reserved)
1111
0000 to
1111
1111
240 to 255
Summary of Contents for G-570U
Page 2: ......
Page 7: ...ZyXEL G 570U User s Guide Safety Warnings 7 This product is recyclable Dispose of it properly...
Page 18: ...ZyXEL G 570U User s Guide 18 List of Figures...
Page 36: ...ZyXEL G 570U User s Guide 36 Chapter 2 Management Computer Setup...
Page 48: ...ZyXEL G 570U User s Guide 48 Chapter 3 Introducing the Web Configurator...
Page 56: ...ZyXEL G 570U User s Guide 56 Chapter 5 System Screen...
Page 92: ...ZyXEL G 570U User s Guide 92 Chapter 6 Wireless Screens...
Page 114: ...ZyXEL G 570U User s Guide 114 Appendix A Product Specifications...
Page 144: ...ZyXEL G 570U User s Guide 144 Appendix C Wireless LANs...
