Wireshark:Capture Interfaces Description Packets Packets/s Stop Intel(R)82567LM t Ne 8441239eb1974 0 Start Options Detail Microsoft 192.1681100 Help Close Figure 4:Wireshark Capture Interface Window 4.You'll see a list of the interfaces on your computer as well as a count of the packets that have been observed on that interface so far.Click on Start for the interface on which you want to begin packet capture(in the case,the Gigabit network Connection).Packet capture will now begin-Wireshark is now capturing all packets being sent/received from/by your computer! 5.Once you begin packet capture.a window similar to that shown in figure 3 will ar This window shows the packets being captured by selecting capture ldown memu and selecting Son you can ston packet canture But don't stor packet canture vet let's capture some interesting g packets first.To do so.wel erate some netw ork traffic.Let's do sing a weh bro which will use the HTTP otocol that we will study in detail i 6 While Wireshark is running,ente the URI http://gaia cs umass.edu/wireshark-labs/INTRO-wireshark-filel.html and have th at page dis played in your browser.In order to display this page,your browser will contact the HTTP server at gaia.cs.umass.edu and exchange HTTP ges with the server in order to download this page,as discussed in section he The Ethemet rmes comtaning thesewell as all other frames passing through your Ethernet adapter)will be captured by Wireshark 7.After your browser has displayed the INTRO-wireshark-filel.html page(it is a simple one line of congratulations).stop Wireshark packet capture by selecting ston in the wireshark canture window The main wireshark window should now look similar to Figure 3.You now have live packet data that contains all protocol messages exchange ed hetween vour and other network entities!The HTTP me ha ith the edu we should pe the list th will h S ckets dis yed as ured re ny othe type na nt protoco ure nough the 00 K wa do wn eb pag the many oth running on you computer that 1 are unseen by the learn much m ore ab thes as we p rogress through th text! w,yo should just be aware that there is often much more going on than"meet's the eye" Figure 4: Wireshark Capture Interface Window 4. You’ll see a list of the interfaces on your computer as well as a count of the packets that have been observed on that interface so far. Click on Start for the interface on which you want to begin packet capture (in the case, the Gigabit network Connection). Packet capture will now begin - Wireshark is now capturing all packets being sent/received from/by your computer! 5. Once you begin packet capture, a window similar to that shown in Figure 3 will appear. This window shows the packets being captured. By selecting Capture pulldown menu and selecting Stop, you can stop packet capture. But don’t stop packet capture yet. Let’s capture some interesting packets first. To do so, we’ll need to generate some network traffic. Let’s do so using a web browser, which will use the HTTP protocol that we will study in detail in class to download content from a website. 6. While Wireshark is running, enter the URL: http://gaia.cs.umass.edu/wireshark-labs/INTRO-wireshark-file1.html and have that page displayed in your browser. In order to display this page, your browser will contact the HTTP server at gaia.cs.umass.edu and exchange HTTP messages with the server in order to download this page, as discussed in section 2.2 of the text. The Ethernet frames containing these HTTP messages (as well as all other frames passing through your Ethernet adapter) will be captured by Wireshark. 7. After your browser has displayed the INTRO-wireshark-file1.html page (it is a simple one line of congratulations), stop Wireshark packet capture by selecting stop in the Wireshark capture window. The main Wireshark window should now look similar to Figure 3. You now have live packet data that contains all protocol messages exchanged between your computer and other network entities! The HTTP message exchanges with the gaia.cs.umass.edu web server should appear somewhere in the listing of packets captured. But there will be many other types of packets displayed as well (see, e.g., the many different protocol types shown in the Protocol column in Figure 3). Even though the only action you took was to download a web page, there were evidently many other protocols running on your computer that are unseen by the user. We’ll learn much more about these protocols as we progress through the text! For now, you should just be aware that there is often much more going on than “meet’s the eye”!