CT320: Network and System Administration

Fall 2018

IP Addresses

See this page as a slide show

CT320 IP Addresses

Port 49757
198.51.100.135
Port 22
203.0.113.42

Format

An IPv4 (as opposed to the newer IPv6) IP address is a 32-bit quantity which represents a host on the internet. It is usually represented as four numbers, each 0–255, separated by dots. For example:

    198.51.100.204

Grouping

Old-Fashioned Classful Addresses

How address ranges used to be allocated
ClassPatternNetworksHosts/networkAddresses
A0nnnnnnn hhhhhhhh hhhhhhhh hhhhhhhh27224 (~16 million)0–127.whatever
B10nnnnnn nnnnnnnn hhhhhhhh hhhhhhhh214216 (65536)128–191.whatever
C110nnnnn nnnnnnnn nnnnnnnn hhhhhhhh22128 (256)192–223.whatever

List of assigned class A networks

Classful no good

Masking

CIDR

CIDR example

Consider the CS network, 129.82.44/23

∴ 129.82.44/23 is the range of addresses 129.82.44.0 … 129.84.45.255.
It contains 129.84.44.whatever and 129.84.45.whatever, for 512 addresses total.

Special classes of addresses

$ host art
art.colostate.edu has address 129.82.184.60
$ host denver
denver.cs.colostate.edu has address 129.82.44.141
$ host tuba
tuba.cs.colostate.edu has address 10.1.44.62

I’m sorry that CSU addresses begin with 129, which is so similar to the 192 that begins one form of private networks.

Stupid IP Address Tricks

These all work in my browser:

Avoid actual links, as the linkcheck program will complain.

    http://www.cs.colostate.edu

    http://%77%77%77%2e%63%73%2e%63%6f%6c%6f%73%74%61%74%65%2e%65%64%75

    http://129.82.45.114

    http://0x81.0x52.0x2d.0x72

    http://0201.0122.055.0162

    http://2169646450

    http://0x81522d72

    http://020124426562

User: Guest

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Modified: 2018-07-13T14:07

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