G-3000H User’s Guide
Appendix H IP Subnetting
257
Since the mask is always a continuous number of ones beginning from the left, followed by a
continuous number of zeros for the remainder of the 32 bit mask, you can simply specify the
number of ones instead of writing the value of each octet. This is usually specified by writing
a “/” followed by the number of bits in the mask after the address.
For example, 192.1.1.0 /25 is equivalent to saying 192.1.1.0 with mask 255.255.255.128.
The following table shows all possible subnet masks for a class “C” address using both
notations.
The first mask shown is the class “C” natural mask. Normally if no mask is specified it is
understood that the natural mask is being used.
Example: Two Subnets
As an example, you have a class “C” address 192.168.1.0 with subnet mask of 255.255.255.0.
The first three octets of the address make up the network number (class “C”). You want to
have two separate networks.
Divide the network 192.168.1.0 into two separate subnets by converting one of the host ID bits
of the IP address to a network number bit. The “borrowed” host ID bit can be either “0” or “1”
thus giving two subnets; 192.168.1.0 with mask 255.255.255.128 and 192.168.1.128 with
mask 255.255.255.128
Table 99
Alternative Subnet Mask Notation
SUBNET MASK IP ADDRESS
SUBNET MASK “1” BITS
LAST OCTET BIT VALUE
255.255.255.0
/24
0000 0000
255.255.255.128
/25
1000 0000
255.255.255.192
/26
1100 0000
255.255.255.224
/27
1110 0000
255.255.255.240
/28
1111 0000
255.255.255.248
/29
1111 1000
255.255.255.252
/30
1111 1100
Table 100
Two Subnets Example
NETWORK NUMBER
HOST ID
IP Address
192.168.1.
0
IP Address (Binary)
11000000.10101000.00000001.
00000000
Subnet Mask
255.255.255.
0
Subnet Mask (Binary)
11111111.11111111.11111111.
00000000
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 ...