IT 315 – Exam 3 Study Guide – Old Dominion University –
Academic Year [Insert Year] – Key Information Technology
Concepts
What does your computer do after it receives a message via TCP? - correct answer ✔✔ It sends
a return segment with the ACK bit set to 1 and the Acknowledgement Number set to the
Sequence Number of the original segment.
What is the purpose of the source and destination port fields in TCP and UDP? - correct answer
✔✔ They identify a specific connection between applications running on different hosts.
When I play minecraft with my son at home, he connects to my computer at IP address
10.0.1.201. However, when I type "What is my IP address" into a Google search box from my
computer, it says my address is 72.218.131.111. Which of the following explains why I am seeing
different values? - correct answer ✔✔ My computers all share the IP address 72.218.131.111
via NAT.
Which of the following is an incorrect pairing of a TCP port number and its use? - correct answer
✔✔ Port 80 - HTTP
Port 6881 - Bit Torrent
Port 25 - SMTP
All of the Above
Which of the following is false about why a UDP datagram has such a smaller header than a TCP
segment? - correct answer ✔✔ UDP is unreliable, so there is no reason to check for errors.
On my computer right now, three applications are running that are all simultaneously using the
Internet: an email client, a web browsing client, and a web server. How does my computer
, decide which application should receive an incoming TCP segment? - correct answer ✔✔ The
destination port number on the TCP segment indicates what application should handle the
incoming segment.
The first time I tried BitTorrent, my Verizon-provided home DSL router crashed because of the
large number of connections that a BitTorrent client makes. Which of the following describes
why a router would crash from too many connections being made? - correct answer ✔✔ The
router's NAT module had too little memory to handle the number of connections made by my
BitTorrent client.
Your friend was charged recently with Criminal Tresspass because he was caught in the Constant
Hall computer lab at 1:05 am. The police claim that he was hiding out in there after wrapping
the lion statue with tiolet paper. If he can prove that he was using the computer to study for his
pre-med class on pathology, the police will drop the charges. In the firewall logs for that day,
there is an entry at 1:04 am with the source address and port 10.22.104.70:53059 and
destination address and port 208.80.154.225:80. 10.22.104.70 is the IP address of the computer
he was seated at, and 208.80.154.225 is the IP address for en.wikipedia.org. Which of the
following is true about providing a reasonable doubt against the police claim that he was not
using the computer? - correct answer ✔✔ It provides doubt because it indicates that someone
used a web browser to access wikipedia.org.
Your friend always has the greatest tech in her house. She has owned a 4K TV for a while, and
Netflix recently started 4K streaming so she checked it out. When she tries to 4K stream,
though, the video stutters even though her Internet connection is 100Mbps and a 4K stream is
only 15Mbps. The normal HD streams that use 7Mbps are very smooth, and she is actually able
to download those more than twice as fast as they play. Since you have taken IT 415, she
considers you a networking expert. Why can't she watch 4K streams normally? - correct answer
✔✔ Her window size field in TCP is set big enough for HD streams, but too small for 4K streams.
I have been helping my son develop a browser-based application. We update the HTML,
Javascript, and CSS files on our home computer, and I want him to be able to test them on his
iPod. Before he can access them on his iPod, though, I have to start up a web server program on
my computer. Why can't he download these files to the web browser on his iPod without my
Academic Year [Insert Year] – Key Information Technology
Concepts
What does your computer do after it receives a message via TCP? - correct answer ✔✔ It sends
a return segment with the ACK bit set to 1 and the Acknowledgement Number set to the
Sequence Number of the original segment.
What is the purpose of the source and destination port fields in TCP and UDP? - correct answer
✔✔ They identify a specific connection between applications running on different hosts.
When I play minecraft with my son at home, he connects to my computer at IP address
10.0.1.201. However, when I type "What is my IP address" into a Google search box from my
computer, it says my address is 72.218.131.111. Which of the following explains why I am seeing
different values? - correct answer ✔✔ My computers all share the IP address 72.218.131.111
via NAT.
Which of the following is an incorrect pairing of a TCP port number and its use? - correct answer
✔✔ Port 80 - HTTP
Port 6881 - Bit Torrent
Port 25 - SMTP
All of the Above
Which of the following is false about why a UDP datagram has such a smaller header than a TCP
segment? - correct answer ✔✔ UDP is unreliable, so there is no reason to check for errors.
On my computer right now, three applications are running that are all simultaneously using the
Internet: an email client, a web browsing client, and a web server. How does my computer
, decide which application should receive an incoming TCP segment? - correct answer ✔✔ The
destination port number on the TCP segment indicates what application should handle the
incoming segment.
The first time I tried BitTorrent, my Verizon-provided home DSL router crashed because of the
large number of connections that a BitTorrent client makes. Which of the following describes
why a router would crash from too many connections being made? - correct answer ✔✔ The
router's NAT module had too little memory to handle the number of connections made by my
BitTorrent client.
Your friend was charged recently with Criminal Tresspass because he was caught in the Constant
Hall computer lab at 1:05 am. The police claim that he was hiding out in there after wrapping
the lion statue with tiolet paper. If he can prove that he was using the computer to study for his
pre-med class on pathology, the police will drop the charges. In the firewall logs for that day,
there is an entry at 1:04 am with the source address and port 10.22.104.70:53059 and
destination address and port 208.80.154.225:80. 10.22.104.70 is the IP address of the computer
he was seated at, and 208.80.154.225 is the IP address for en.wikipedia.org. Which of the
following is true about providing a reasonable doubt against the police claim that he was not
using the computer? - correct answer ✔✔ It provides doubt because it indicates that someone
used a web browser to access wikipedia.org.
Your friend always has the greatest tech in her house. She has owned a 4K TV for a while, and
Netflix recently started 4K streaming so she checked it out. When she tries to 4K stream,
though, the video stutters even though her Internet connection is 100Mbps and a 4K stream is
only 15Mbps. The normal HD streams that use 7Mbps are very smooth, and she is actually able
to download those more than twice as fast as they play. Since you have taken IT 415, she
considers you a networking expert. Why can't she watch 4K streams normally? - correct answer
✔✔ Her window size field in TCP is set big enough for HD streams, but too small for 4K streams.
I have been helping my son develop a browser-based application. We update the HTML,
Javascript, and CSS files on our home computer, and I want him to be able to test them on his
iPod. Before he can access them on his iPod, though, I have to start up a web server program on
my computer. Why can't he download these files to the web browser on his iPod without my
