Midterm Review
Dr. Philip Cannata
1
Be sure to study all of the Homework and Quiz solutions.
Dr. Philip Cannata
2
Carefully review the following sections in “Top-Down”.
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1.1.3 What is a Protocol?
1.3.1 Packet Switching
1.3.3 A Network of Networks
1.4.1 Overview of Delay in Packet-Switched Networks
1.5 Protocol Layers and Their Service Models
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2. Intro
2.1 Principles of Network Applications
2.2 HTTP
2.3 FTP
2.4 Intro
2.4.1 SMTP
2.4.2 Comparison to HTTP
2.5 DNS
Dr. Philip Cannata
3
Python Programs to know inside and out
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SimpleWebClient.py on the class calendar
WebServer.py
UDPPingerClient.py
UDPPingerServer.py
From “Foundations of Python Network Programming”:
• search4.py on the class calendar
• Page137.py on the class calendar for possible extra credit
Dr. Philip Cannata
4
Carefully Review the following from the Companion Website.
Video Notes
Chapter 1
• Propagation Delay and Transmission Delay
• Traceroute
Chapter 2
• Introduction to Wireshark and HTTP
Wireshark Labs (I passed out hardcopy solutions for these.)
• HTTP
• DNS – Note: for the last part of this lab I think he should
have done:
nslookup mit.edu bitsy.mit.edu
see the next page for a better example.
Dr. Philip Cannata
5
Understand the following nslookup interaction.
Phils-MacBook-Pro:~ pcannata$ nslookup utexas.edu
Server:
209.18.47.61
Address:
209.18.47.61#53
Non-authoritative answer:
Name:
utexas.edu
Address: 128.83.40.144
Name:
utexas.edu
Address: 128.83.40.145
Name:
utexas.edu
Address: 128.83.40.146
Name:
utexas.edu
Address: 128.83.40.147
The following steps will get an authoritative answer
Phils-MacBook-Pro:~ pcannata$ nslookup -type=NS utexas.edu
Server:
209.18.47.61
Address:
209.18.47.61#53
Non-authoritative answer:
utexas.edu nameserver = chisos.ots.utexas.edu.
utexas.edu nameserver = dns1.illinois.edu.
utexas.edu nameserver = dns2.illinois.edu.
utexas.edu nameserver = marianas.its.utexas.edu.
utexas.edu nameserver = glass.its.utexas.edu.
Authoritative answers can be found from:
Phils-MacBook-Pro:~ pcannata$ nslookup utexas.edu chisos.ots.utexas.edu
Server:
chisos.ots.utexas.edu
Address:
128.83.185.39#53
Dr. Philip Cannata
Name:
utexas.edu
Address: 128.83.40.146
Name:
utexas.edu
Address: 128.83.40.147
Name:
utexas.edu
Address: 128.83.40.144
Name:
utexas.edu
Address: 128.83.40.145
6