Dr. Mark Humphrys School of Computing. Dublin City University. My big idea: Ancient Brain Search:
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Network classes

The old way of handing out IP addresses.
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Summary from here.

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Example - DCU's block of addresses

DCU has the following block of addresses:
```Dublin City University (NET-DCU-NET)
Glasnevin
Dublin, 9
IE

Netname: DCU-NET
Netblock: 136.206.0.0 - 136.206.255.255
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i.e. room for 2562 = 65,536 addresses.

DCU addresses run from:
136.206.0.0     to:
136.206.255.255
In binary, from:
1000 1000 1100 1110 0000 0000 0000 0000     to:
1000 1000 1100 1110 1111 1111 1111 1111
See IP decimal-binary table

First 16 bits are the DCU network number 136.206.
This is in binary:
1000 1000 1100 1110
Second 16 bits are the host number on that network.

This is a Class B network.
To be precise, the leading 10 indicates Class B, then the network number is the 14 bit:
00 1000 1100 1110
So a DCU address is:
Class B identifier, DCU network, machine number n:
10 00 1000 1100 1110 nnnn nnnn nnnn nnnn

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IP address shows network class.
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