In class, we will try some live demos to explore the inner workings of the Internet.
Addressing: IP addresses vs. Domain names
Packet Routing
There are a variety of tools available, both as utilities on the computer or public websites.
OSX Operating System:
You can also use the underlying commandline tools directly from a Terminal window.
host name
returns the IP address(es) associated with the given host hame.
host IPaddress
returns the name(s) assocaited with the given IP address.
traceroute name
traceroute IPaddress
shows the series of hops which is used when sending packets from your local machine to the specified machine.
(an exceprt from the manual page for traceroute)
These tools and others can be started with a GUI interface called "Network Utility" which you will find in the Applications/Utilities folder. (that software essentially places the output generated by the underlying tools into a window).
Windows Operating System:
The traceroute program is known as tracert on Windows. It can be run at the Command Prompt.
Tools on the internet (often free demos, selling commercial services):
Summary of Class A, B, C network assignments: http://www.flumps.org/ip