236
Appendix F IP subnetting
N0115791
192.168.1.0 with mask 255.255.255.128 is the subnet itself, and 192.168.1.127
with mask 255.255.255.128 is the directed broadcast address for the first subnet.
Therefore, the lowest IP address that can be assigned to an actual host for the first
subnet is 192.168.1.1 and the highest is 192.168.1.126. Similarly the host ID
range for the second subnet is 192.168.1.129 to 192.168.1.254.
Example: four subnets
The above example illustrated using a 25-bit subnet mask to divide a class C
address space into two subnets. Similarly to divide a class C address into four
subnets, you need to borrow two host ID bits to give four possible combinations
of 00, 01, 10 and 11. The subnet mask is 26 bits
(11111111.11111111.11111111.
11
000000) or 255.255.255.192. Each subnet
contains 6 host ID bits, giving 2
6
-2 or 62 hosts for each subnet (all 0s is the subnet
itself, all 1s is the broadcast address on the subnet).
Table 49
Subnet 1
Network number
Last octet bit value
IP Address
192.168.1.
0
IP Address (Binary)
11000000.10101000.00000001.
00
000000
Subnet Mask (Binary)
11111111.11111111.11111111.
11
000000
Subnet Address: 192.168.1.0
Lowest Host ID: 192.168.1.1
Broadcast Address: 192.168.1.63 Highest Host ID: 192.168.1.62
Table 50
Subnet 2
Network number
Last octet bit value
IP Address
192.168.1.
64
IP Address (Binary)
11000000.10101000.00000001.
01
000000
Subnet Mask (Binary)
11111111.11111111.11111111.
11
000000
Subnet Address: 192.168.1.64
Lowest Host ID: 192.168.1.65
Broadcast Address:
192.168.1.127
Highest Host ID: 192.168.1.126
Содержание BCM50a
Страница 18: ...18 Figures N0115791 ...
Страница 22: ...22 Tables N0115791 ...
Страница 28: ...28 Preface N0115791 ...
Страница 44: ...44 Chapter 2 Introducing the SMT N0115791 SMT menus at a glance Figure 6 SMT overview ...
Страница 52: ...52 Chapter 2 SMT menu 1 general setup N0115791 ...
Страница 64: ...64 Chapter 4 LAN setup N0115791 ...
Страница 68: ...68 Chapter 5 Internet access N0115791 ...
Страница 82: ...82 Chapter 6 Remote Node setup N0115791 ...
Страница 114: ...114 Chapter 9 Network Address Translation NAT N0115791 ...
Страница 140: ...140 Chapter 12 SNMP Configuration N0115791 ...
Страница 144: ...144 Chapter 13 System security N0115791 ...
Страница 160: ...160 Chapter 14 System information and diagnosis N0115791 ...
Страница 174: ...174 Chapter 15 Firmware and configuration file maintenance N0115791 ...
Страница 188: ...188 Chapter 17 Remote Management N0115791 ...
Страница 208: ...208 Appendix B Triangle Route N0115791 ...
Страница 228: ...228 Appendix D PPPoE N0115791 ...
Страница 230: ...230 Appendix E Hardware specifications N0115791 ...
Страница 240: ...240 Appendix F IP subnetting N0115791 ...
Страница 278: ...278 Appendix G Command Interpreter N0115791 ...
Страница 308: ...308 Appendix J Log descriptions N0115791 ...
Страница 310: ...310 Appendix K Brute force password guessing protection N0115791 ...