Transcript COMP 3630 - The Internet

COMP 3630 - The Internet
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Name: Dr. Joseph NG
Office: R707 (Run Run Shaw Building)
Phone: 2339-7864
Email: [email protected]
HomePage: http://www.comp.hkbu.edu.hk/~jng
ICQ: I am not going to tell you!
• Planned Conference Trip:
• November 30 --- December 5 (Phoenix, Arizona,
U.S.A.)
• Guest Lecture by Mr. Y. K. Chan on December 3.
COMP 3630 - The Internet
• Subject Contents (4 weeks left)
– The Cyber Map Project
• Use of ping, traceroute from UNIX, and tracert
from NT
• Internet application using cgi or perl
– Internet Applications Case Studies
• Search Engines (Yahoo vs. Lycos)
• Interactive TV (iTV)
• Emerging Technologies leading to Electronic
Commerce
• Hands-on Experience for PGP (Y.K. Chan)
COMP 3630 - The Internet
• The Cyber Map Project
– Project Descriptions
• Given the host address of the Top-22 Universities in
U.S.A.;
• Use traceroute (unix) or tracert (NT) to find out the routes
from HKBU to each of the address and record the
gateways in between;
• Using the ping command to estimate the round trip delay
from HKBU to each gateway;
• Construct a graph to represent the connectivity between
HKBU and these 25 Universities;
• The graph is updated automatically and periodically;
• The delay and connectivity information is made available
through a web page;
COMP 3630 - The Internet
• The Cyber Map Project
– Top-22 Universities of U.S.A.
• http://www.usnews.com/usnews/edu/college/rankings/cat1
3wi.htm (courtesy to US News)
1. Massachusetts Inst. of Technology
2. Stanford University (CA)
2. University of California Berkeley
4. California Institute of Technology
4. University of Illinois Urbana-Champaign
6. University of Michigan Ann Arbor
7. Carnegie Mellon University (PA)
7. Cornell University (NY)
7. Georgia Institute of Technology
10. University of Texas Austin
11. Purdue University West Lafayette (IN)
12. Princeton University (NJ)
12. University of Wisconsin Madison
14. Johns Hopkins University (MD)
14. Northwestern University (IL)
14. Pennsylvania State University
14. Rensselaer Polytechnic Inst. (NY)
18. Rice University (TX)
18. Texas A&M University College Station
18. University of California Los Angeles
18. University of Minnesota Twin Cities
18. Virginia Tech
COMP 3630 - The Internet
• The Cyber Map Project
– Useful commands from unix and Windows NT
• ping -- ping utilizes the ICMP protocol's
ECHO_REQUEST datagram to elicit an ICMP
ECHO_RESPONSE from the specified host or network
gateway.
• traceroute -- traceroute in unix and tracert in Windows
NT provide the same function. Traceroute utilizes the IP
protocol `time to live' field and attempts to elicit an ICMP
TIME_EXCEEDED response from each gateway along
the path to some host.
• netstat -- netstat basically shows the network status.
Depending on the options you select, it displays the state
of all sockets and all routing table entries; normally only
interface, host, network and default routes are shown.
Note: consult the man pages for these commands.
COMP 3630 - The Internet
• The Cyber Map Project
– Use Yahoo or Lycos and search for traceroute and related
applications and see if you have any new idea in working on
your Cyber Map project.
– For Examples (from Lycos)
• NeoTrace
• GTrace
• VisualRoute
• Cybergeography -- a cool site (http://www.cybergeography.org/)
– Article: “MAPPING THE INTERNET
WITH TRACEROUTE” by Jack Rickard
– Type in “traceroute” from Yahoo will give you a list of
traceroute servers.
COMP 3630 - The Internet
• The Cyber Map Project
– Programming
• Although you can easily find the source code of “ping”
and “traceroute” from the web or from the book “unix
network programming” by Richard Stevens, you may
want to do the project in a quick and dirty way by simply
writing a C program with and make use of the “system”
call.
• So call traceroute from your program and redirect the
output to a tmp file, and later on read back this tmp file
and get the gateway information.
• Use “ping” to update the delay information automatically
and periodically.
• Design a simple web page for query.