Working out
the range of addresses for a given IP/ subnet mask pair.
Let us use the following
address:
192.168.100.0 /22
Part of the address is to
denote the network, the rest is to denote the host(s).
Key
blue = network
Red = host
Firstly rewrite the address
as binary – use a calculator if you need to. Then write the subnet mask below
the IP address.
IP address 11000000.10101000.01100100.00000000
Subnet Mask 11111111.11111111.11111100.00000000
To obtain the last address on
the network, substitute the last 10 bits (in red) for 1s. Now convert back to
decimal.
Last address 11000000.10101000.01100111.11111111
Decimal 192. 168. 103. 255
We can now see that
192.168.100.0 /22 runs from
192.168.100.0 to
192.168.103.255
Note that this table relates
to the address range above only
|
SM |
/22 |
/23 |
/24 |
/25 |
/26 |
/27 |
/28 |
/29 |
/30 |
|
Host bits |
10 |
9 |
8 |
7 |
6 |
5 |
4 |
3 |
2 |
|
Number of networks Available for 192.168.100.0
/22 |
1 |
2 |
4 |
8 |
16 |
32 |
64 |
128 |
256 |
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