260
Appendix F IP subnetting
NN47923-501
Table 54
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.
Table 54
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
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 252
Page 14: ...14 Contents NN47923 501 ...
Page 20: ...20 Figures NN47923 501 ...
Page 24: ...24 Tables NN47923 501 ...
Page 30: ...30 Preface NN47923 501 ...
Page 42: ...42 Chapter 1 Getting to know your Nortel Business Secure Router 252 NN47923 501 ...
Page 48: ...48 Chapter 2 Introducing the SMT NN47923 501 SMT menus at a glance Figure 6 SMT overview ...
Page 72: ...72 Chapter 3 WAN and Dial Backup Setup NN47923 501 ...
Page 80: ...80 Chapter 4 LAN setup NN47923 501 ...
Page 84: ...84 Chapter 5 Internet access NN47923 501 ...
Page 98: ...98 Chapter 6 Remote Node setup NN47923 501 ...
Page 102: ...102 Chapter 7 IP Static Route Setup NN47923 501 ...
Page 130: ...130 Chapter 9 Network Address Translation NAT NN47923 501 ...
Page 156: ...156 Chapter 12 SNMP Configuration NN47923 501 ...
Page 178: ...178 Chapter 14 System information and diagnosis NN47923 501 ...
Page 198: ...198 Chapter 15 Firmware and configuration file maintenance NN47923 501 ...
Page 212: ...212 Chapter 17 Remote Management NN47923 501 ...
Page 232: ...232 Appendix B Triangle Route NN47923 501 ...
Page 252: ...252 Appendix D PPPoE NN47923 501 ...
Page 256: ...256 Appendix E Hardware specifications NN47923 501 ...
Page 266: ...266 Appendix F IP subnetting NN47923 501 ...
Page 308: ...308 Appendix H NetBIOS filter commands NN47923 501 ...
Page 332: ...332 Appendix K Brute force password guessing protection NN47923 501 ...