Appendix E IP Subnetting
P-660HWP-Dx User’s Guide
37
By convention, subnet masks always consist of a continuous sequence of ones beginning from
the leftmost bit of the mask, followed by a continuous sequence of zeros, for a total number of
32 bits.
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”).
To make two 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 157
Alternative Subnet Mask Notation
SUBNET MASK
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 158
Two Subnets Example
IP/SUBNET MASK
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 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 ...