Readings
from the
text book:
Sections 1.1 - 1.5 |
Module
1
is
essentially the first five sections from the text, with some
supplementary material. The goal is to familiarize you with the world
of Computer Networks, its key players and some of the tools of the
trade. Pay special attention to understanding the difference between Packet
Switching with message
segmentation and Circuit
Switching, and why Packet
Switching is preferred in most Internet as well as telephony
applications - see section 1.3 of the text. |
See
these
supplementary notes. |
Unix
tools.
These are common
tools used by network administrators. You should
become familiar with them. |
login
to your cs
account
on 137.140.4.101 and execute the following commands and study the
output:
traceroute
www.yahoo.com
netstat
-an
netstat
-rn
sudo
exec-dumpICMP
sudo
exec-dumpTCP
sudo
exec-dumpUDP
We
will learn how to read and interpret the output from these tools later
in the course
exec-dumpXXX
commands are modified versions of tcpdump
to capture network packets. tcpdump
is a packet capture software widely available for many platforms. You
do not have permission to execute tcpdump
on campus machines for security reasons. Instead, you can
execute the modified versions as shown above, with the sudo prefix.
sudo
is a unix tool that allows ordinary users to execute privileged
commands under certain conditions.
|
traceroute
traces the route from your host to another host.
netstat
is very versatile. Do man
netstat at the unix prompt to
check man pages for
this command.
On
most Windows machines, you can open a Command Window and execute netstat
|
| Ethereal |
Ethereal
is a network packet capture and analysis tool available for Linux/Unix
and Windows platforms. It can be freely downloaded from
http://ethereal.com. You will also need the libpcap libraries from
http://winpcap.polito.it/install/Default.htm.
Please
download and install Ethereal on your machine. It will be quite useful
for this course, as well as for other purposes.
|
Ethereal
is perhaps the best network packet analyzer around. It has a pretty
easy user interface. See documetation at
http://www.ethereal.com/docs/user-guide-sp/
|
| You
should either already be familiar with the terms listed in the
table to the right, or you should become familiar with them. |
- Bandwidth
of a
link
- Connection-oriented
and Connectionless services
- Datagram
services
- Bitstream
services
- Host
- Router
- Route
- Packet
- Protocol
- Reliable/Unreliable
services
- TCP,
UDP and IP
protocols
- Internet
Standards
- Internet
Engineering Task Force(IETF)
- Request
for
Comments (RFCs)
- International
Standards Organization (ISO)
|
A
brief summary of these terms |
| Check
the following URLs: |
www.faqs.org
-- searchable list of RFCs. A very useful site.
Organizations
that
set standards for the Internet as well as other stuff.
- www.ietf.org
- www.iso.org
- www.iec.ch
- www.ieee.org
- www.icann.org
|
|