computer network homework 2 - seoul national...
TRANSCRIPT
Computer Network
Homework 2
Chong-kwon Kim
2018
Aims, Dues, …
Aims
– To learn the use of a protocol analyzer
– Examine how various protocols operate
Due
– Oct. 18th 11:59PM
Submission
– To [email protected]
– Mail subject : CN Protocol HW – 2018-00000 홍길동
Question
– Via E-mail
SNU SCONE lab.2
Protocol Analyzer
A tool that captures packets passing through networks
and, show information contained in headers, and
perform basic statistical analysis
One of the most important tools
– To learn how protocols work
– To debug protocols or applications you design/implement
– To measure performance
– …
There are several protocol analyzers
The most popular one is Wireshark, a freeware
– Download at https://www.wireshark.org/
SNU SCONE lab.3
How to start Wireshark - Windows
Setup option
SNU SCONE lab.4
How to start Wireshark - Windows
Setup option
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How to start Wireshark - Windows
SNU SCONE lab.6
Select - eth0(or 이더넷 1, 이더넷 2, … )
- Wlan 0(or Wi-Fi)
Start Capture!
airpcap is required to
capture WLAN
Main
How to start Wireshark - Ubuntu
sudo apt-get install wireshark
SNU SCONE lab.7
How to start Wireshark
SNU SCONE lab.8
Example of captured packet
How to start Wireshark
SNU SCONE lab.9
Filter (Example of TCP)
How to start Wireshark
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Fields in protocol headers
SNU SCONE lab.
What packets to capture and analyze?
Capture and analyze the protocols
– Ethernet, WLAN
– IP
– ARP
– ICMP(such as ping, traceroute)
For each protocol
– Describe interactions between two communication entities
– Details of fields in protocol headers
SNU SCONE lab.11
Use of “airpcap”
We should share one airpcap
– Limit: at most two times per person during
– Weekdays between 9.27 ~ 10.18 (09:00~12:00, 19:00~21:00)
– Bldg.302 310-1
You should make reservation before use
– Via E-mail
SNU SCONE lab.12
Report
Limit 15 page in single column(font size of 10)
File name: your-name_student-id.pdf
Each report should include
– How you setup devices to capture packets(frames)
– How you generate packets(frames)
– Protocols you analyzed
13SNU SCONE lab.