Appendix B IP Addresses and Subnetting
AMG1302-T10A User’s Guide
253
Subnet masks are expressed in dotted decimal notation just like IP addresses. The following
examples show the binary and decimal notation for 8-bit, 16-bit, 24-bit and 29-bit subnet masks.
Network Size
The size of the network number determines the maximum number of possible hosts you can have
on your network. The larger the number of network number bits, the smaller the number of
remaining host ID bits.
An IP address with host IDs of all zeros is the IP address of the network (192.168.1.0 with a 24-bit
subnet mask, for example). An IP address with host IDs of all ones is the broadcast address for that
network (192.168.1.255 with a 24-bit subnet mask, for example).
As these two IP addresses cannot be used for individual hosts, calculate the maximum number of
possible hosts in a network as follows:
Notation
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 subnet mask 255.255.255.128.
The following table shows some possible subnet masks using both notations.
Table 101
Subnet Masks
BINARY
DECIMAL
1ST
OCTET
2ND
OCTET
3RD
OCTET
4TH OCTET
8-bit mask
11111111
00000000
00000000
00000000
255.0.0.0
16-bit mask 11111111
11111111
00000000
00000000
255.255.0.0
24-bit mask 11111111
11111111
11111111
00000000
255.255.255.0
29-bit mask 11111111
11111111
11111111
11111000
255.255.255.248
Table 102
Maximum Host Numbers
SUBNET MASK
HOST ID SIZE
MAXIMUM NUMBER OF HOSTS
8 bits
255.0.0.0
24 bits
2
24
– 2
16777214
16 bits
255.255.0.0
16 bits
2
16
– 2
65534
24 bits
255.255.255.0
8 bits
2
8
– 2
254
29 bits
255.255.255.24
8
3 bits
2
3
– 2
6
Table 103
Alternative Subnet Mask Notation
SUBNET MASK
ALTERNATIVE
NOTATION
LAST OCTET
(BINARY)
LAST OCTET
(DECIMAL)
255.255.255.0
/24
0000 0000
0
255.255.255.128
/25
1000 0000
128
255.255.255.192
/26
1100 0000
192
Summary of Contents for AMG1302-T10A
Page 4: ...Contents Overview AMG1302 T10A User s Guide 4 ...
Page 12: ...Table of Contents AMG1302 T10A User s Guide 12 ...
Page 13: ...13 PART I User s Guide ...
Page 14: ...14 ...
Page 20: ...Chapter 1 Introduction AMG1302 T10A User s Guide 20 ...
Page 52: ...Chapter 4 Tutorials AMG1302 T10A User s Guide 52 ...
Page 53: ...53 PART II Technical Reference ...
Page 54: ...54 ...
Page 126: ...Chapter 8 Wireless LAN AMG1302 T10A User s Guide 126 ...
Page 140: ...Chapter 9 Network Address Translation NAT AMG1302 T10A User s Guide 140 ...
Page 158: ...Chapter 11 Filters AMG1302 T10A User s Guide 158 ...
Page 162: ...Chapter 12 Static Route AMG1302 T10A User s Guide 162 ...
Page 166: ...Chapter 13 Port Binding AMG1302 T10A User s Guide 166 ...
Page 176: ...Chapter 15 Quality of Service QoS AMG1302 T10A User s Guide 176 ...
Page 198: ...Chapter 18 Universal Plug and Play UPnP AMG1302 T10A User s Guide 198 ...
Page 202: ...Chapter 19 CWMP AMG1302 T10A User s Guide 202 ...
Page 206: ...Chapter 20 System Settings AMG1302 T10A User s Guide 206 ...
Page 216: ...Chapter 21 Logs AMG1302 T10A User s Guide 216 ...
Page 266: ...Appendix C Pop up Windows JavaScripts and Java Permissions AMG1302 T10A User s Guide 266 ...
Page 280: ...Appendix D Wireless LANs AMG1302 T10A User s Guide 280 ...
Page 290: ...Appendix E IPv6 AMG1302 T10A User s Guide 290 ...
Page 322: ...Appendix G Legal InformationSafety Warnings AMG1302 T10A User s Guide 322 ...