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Appendix B IP Addresses and Subnetting
STB-1001S2 User’s Guide
67
Figure 53
Subnetting Example: After Subnetting
In a 25-bit subnet the host ID has 7 bits, so each sub-network has a maximum of 2
7
– 2 or 126
possible hosts (a host ID of all zeroes is the subnet’s address itself, all ones is the subnet’s
broadcast address).
192.168.1.0 with mask 255.255.255.128 is subnet
A
itself, and 192.168.1.127 with mask
255.255.255.128 is its broadcast address. Therefore, the lowest IP address that can be assigned
to an actual host for subnet
A
is 192.168.1.1 and the highest is 192.168.1.126.
Similarly, the host ID range for subnet
B
is 192.168.1.129 to 192.168.1.254.
Example: Four Subnets
The previous example illustrated using a 25-bit subnet mask to divide a 24-bit address into two
subnets. Similarly, to divide a 24-bit address into four subnets, you need to “borrow” two host
ID bits to give four possible combinations (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 (a host ID of all
zeroes is the subnet itself, all ones is the subnet’s broadcast address).
Table 18
Subnet 1
IP/SUBNET MASK
NETWORK NUMBER
LAST OCTET BIT
VALUE
IP Address (Decimal)
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
Summary of Contents for STB-1001S2
Page 2: ......
Page 8: ...Contents Overview STB 1001S2 User s Guide 8 ...
Page 14: ...List of Tables STB 1001S2 User s Guide 14 ...
Page 16: ...16 ...
Page 20: ...Chapter 1 Introducing the STB STB 1001S2 User s Guide 20 ...
Page 34: ...Chapter 3 Troubleshooting STB 1001S2 User s Guide 34 ...
Page 40: ...40 ...
Page 62: ...Appendix A Setting up Your Computer s IP Address STB 1001S2 User s Guide 62 ...
Page 76: ...Appendix C Legal Information STB 1001S2 User s Guide 76 ...