Appendix E IP Subnetting
P-660HWP-Dx User’s Guide
36
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.
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 bits. If a bit in the subnet mask 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 like IP addresses. 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.
Table 155
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
Table 156
“Natural” Masks
CLASS
NATURAL MASK
A
255.0.0.0
B
255.255.0.0
C
255.255.255.0
Summary of Contents for 802.11g HomePlug AV ADSL2+ Gateway P-660HWP-Dx
Page 2: ......
Page 7: ...Safety Warnings P 660HWP Dx User s Guide 39 ...
Page 8: ...Safety Warnings P 660HWP Dx User s Guide 40 ...
Page 10: ...Contents Overview P 660HWP Dx User s Guide 36 ...
Page 20: ...Table of Contents P 660HWP Dx User s Guide 44 ...
Page 32: ...List of Tables P 660HWP Dx User s Guide 40 ...
Page 33: ...35 PART I Introduction Introducing the P 660HWP Dx 35 Introducing the Web Configurator 43 ...
Page 34: ...36 ...
Page 42: ...Chapter 1 Introducing the P 660HWP Dx P 660HWP Dx User s Guide 42 ...
Page 56: ...Chapter 2 Introducing the Web Configurator P 660HWP Dx User s Guide 48 ...
Page 58: ...36 ...
Page 78: ...Chapter 4 Bandwidth Management Wizard P 660HWP Dx User s Guide 54 ...
Page 80: ...36 ...
Page 98: ...Chapter 5 WAN Setup P 660HWP Dx User s Guide 52 ...
Page 142: ...Chapter 8 Powerline P 660HWP Dx User s Guide 42 ...
Page 156: ...36 ...
Page 176: ...Chapter 11 Firewall Configuration P 660HWP Dx User s Guide 54 Figure 99 Firewall Edit Rule ...
Page 190: ...Chapter 11 Firewall Configuration P 660HWP Dx User s Guide 68 ...
Page 194: ...Chapter 12 Content Filtering P 660HWP Dx User s Guide 72 ...
Page 218: ...36 ...
Page 222: ...Chapter 14 Static Route P 660HWP Dx User s Guide 38 ...
Page 238: ...Chapter 16 Dynamic DNS Setup P 660HWP Dx User s Guide 38 ...
Page 250: ...Chapter 17 Remote Management Configuration P 660HWP Dx User s Guide 46 ...
Page 262: ...Chapter 18 Universal Plug and Play UPnP P 660HWP Dx User s Guide 58 ...
Page 264: ...36 ...
Page 270: ...Chapter 19 System P 660HWP Dx User s Guide 40 ...
Page 288: ...Chapter 20 Logs P 660HWP Dx User s Guide 52 ...
Page 294: ...Chapter 21 Tools P 660HWP Dx User s Guide 40 ...
Page 304: ...36 ...
Page 340: ...Appendix C Internal SPTGEN P 660HWP Dx User s Guide 50 ...
Page 364: ...Appendix E IP Subnetting P 660HWP Dx User s Guide 42 ...
Page 368: ...Appendix F Command Interpreter P 660HWP Dx User s Guide 38 ...
Page 388: ...Appendix K Legal Information P 660HWP Dx User s Guide 38 ...
Page 394: ...Appendix L Customer Support P 660HWP Dx User s Guide 40 ...
Page 402: ...Index P 660HWP Dx User s Guide 42 ...