G-3000H User’s Guide
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Appendix H IP Subnetting
Since the first octet of a class “A” IP address must contain a “0”, the first octet of a class “A”
address can have a value of 0 to 127.
Similarly the first octet of a class “B” must begin with “10”, therefore the first octet of a class
“B” address has a valid range of 128 to 191. The first octet of a class “C” address begins with
“110”, and therefore has a range of 192 to 223.
Subnet Masks
A subnet mask is used to determine which bits are part of the network number, and which bits
are part of the host ID (using a logical AND operation). A subnet mask has 32 is a “1” then
the corresponding bit in the IP address is part of the network number. If a bit in the subnet
mask is “0” then the corresponding bit in the IP address is part of the host ID.
Subnet masks are expressed in dotted decimal notation just as IP addresses are. The “natural”
masks for class A, B and C IP addresses are as follows.
Subnetting
With subnetting, the class arrangement of an IP address is ignored. For example, a class C
address no longer has to have 24 bits of network number and 8 bits of host ID. With
subnetting, some of the host ID bits are converted into network number bits. By convention,
subnet masks always consist of a continuous sequence of ones beginning from the left most bit
of the mask, followed by a continuous sequence of zeros, for a total number of 32 bits.
Table 97
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
Table 98
“Natural” Masks
CLASS
NATURAL MASK
A
255.0.0.0
B
255.255.0.0
C
255.255.255.0
Summary of Contents for ZyAIR G-3000H
Page 1: ...G 3000H 802 11g Wireless Access Point User s Guide Version 3 50 1 2006 ...
Page 22: ...G 3000H User s Guide 22 List of Figures ...
Page 26: ...G 3000H User s Guide 26 List of Tables ...
Page 114: ...G 3000H User s Guide 114 Chapter 9 VLAN ...
Page 134: ...G 3000H User s Guide 134 Chapter 11 Certificates ...
Page 164: ...G 3000H User s Guide 164 Chapter 15 Introducing the SMT ...
Page 180: ...G 3000H User s Guide 180 Chapter 17 LAN Setup ...
Page 218: ...G 3000H User s Guide 218 Chapter 24 System Maintenance and Information ...
Page 224: ...G 3000H User s Guide 224 Appendix C Power over Ethernet PoE Specifications ...
Page 226: ...G 3000H User s Guide 226 Appendix D Brute Force Password Guessing Protection ...
Page 238: ...G 3000H User s Guide 238 Appendix E Setting up Your Computer s IP Address ...
Page 242: ...G 3000H User s Guide 242 Appendix F IP Address Assignment Conflicts ...
Page 254: ...G 3000H User s Guide 254 Appendix G Wireless LANs ...
Page 262: ...G 3000H User s Guide 262 Appendix H IP Subnetting ...
Page 264: ...G 3000H User s Guide 264 Appendix I Command Interpreter ...
Page 268: ...G 3000H User s Guide 268 Appendix J Log Descriptions ...
Page 272: ...G 3000H User s Guide 272 Appendix L Power Adaptor Specifications ...
Page 280: ...G 3000H User s Guide 280 Appendix M Text File Based Auto Configuration ...
Page 294: ...G 3000H User s Guide 294 Appendix N Wireless LAN Manager ...
Page 299: ...G 3000H User s Guide Index 299 ZyNOS F W Version 196 zyxel prowireless mib 287 ...