P-660R-T Series User’s Guide
275
Appendix C 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.
Table 87
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
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.
Table 88
“Natural” Masks
CLASS
NATURAL MASK
A
255.0.0.0
B
255.255.0.0
C
255.255.255.0
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.
Содержание ADSL2+ 4-port Gateway P-660H-D Series
Страница 1: ...P 660R T Series ADSL2 Ethernet Gateway User s Guide Version 3 40 6 2005 ...
Страница 23: ...P 660R T Series User s Guide 23 ...
Страница 27: ...P 660R T Series User s Guide 27 ...
Страница 31: ...P 660R T Series User s Guide 31 Introduction to DSL ...
Страница 39: ...P 660R T Series User s Guide 39 Chapter 1 Getting To Know Your Prestige ...
Страница 57: ...P 660R T Series User s Guide 57 Chapter 4 Password Setup ...
Страница 65: ...P 660R T Series User s Guide 65 Chapter 5 LAN Setup ...
Страница 75: ...P 660R T Series User s Guide 75 Chapter 6 WAN Setup ...
Страница 87: ...P 660R T Series User s Guide 87 Chapter 7 Network Address Translation NAT Screens ...
Страница 95: ...P 660R T Series User s Guide 95 Chapter 10 Remote Management Configuration ...
Страница 107: ...P 660R T Series User s Guide 107 Chapter 11 Universal Plug and Play UPnP ...
Страница 127: ...P 660R T Series User s Guide 127 Chapter 14 Menu 1 General Setup ...
Страница 131: ...P 660R T Series User s Guide 131 Chapter 15 Menu 2 WAN Backup Setup ...
Страница 135: ...P 660R T Series User s Guide 135 Chapter 16 Menu 3 LAN Setup ...
Страница 157: ...P 660R T Series User s Guide 157 Chapter 19 Static Route Setup ...
Страница 161: ...P 660R T Series User s Guide 161 Chapter 20 Bridging Setup ...
Страница 177: ...P 660R T Series User s Guide 177 Chapter 21 Network Address Translation NAT ...
Страница 205: ...P 660R T Series User s Guide 205 Chapter 24 System Information and Diagnosis ...
Страница 217: ...P 660R T Series User s Guide 217 Chapter 25 Firmware and Configuration File Maintenance ...
Страница 223: ...P 660R T Series User s Guide 223 Chapter 26 System Maintenance ...
Страница 227: ...P 660R T Series User s Guide 227 Chapter 27 Remote Management ...
Страница 237: ...P 660R T Series User s Guide 237 Chapter 28 IP Policy Routing ...
Страница 241: ...P 660R T Series User s Guide 241 Chapter 29 Call Scheduling ...
Страница 253: ...P 660R T Series User s Guide 253 Chapter 30 Troubleshooting Figure 173 Java Sun ...
Страница 257: ...P 660R T Series User s Guide 257 Appendix A ...
Страница 281: ...P 660R T Series User s Guide 281 Appendix C IP Subnetting ...
Страница 284: ...P 660R T Series User s Guide Appendix D Splitters and Microfilters 284 ...
Страница 285: ...P 660R T Series User s Guide 285 Appendix D Splitters and Microfilters ...
Страница 287: ...P 660R T Series User s Guide 287 Appendix E Command Interpreter ...
Страница 295: ...P 660R T Series User s Guide 295 Virtual Circuit Topology ...