Hello, I just trained with the old quizzes and have some questions
1) You type a URL in your web client (for the first time). How many HTTP requests does the web client generate?
A: 1 or more
Question: 1 is for the base file and possibly more for referenced files on the base file?
2) You type a URL in your web client. What is the minimum number of DNS requests that your computer may generate?
A: 0
Question: I though it is 1, since the client DNS request the data from a local DNS that may have it cached? What am I missing? That my browser itself may cache it?
3) A massive denial-of-service (DoS) attack starts against the epfl.ch authoritative DNS servers. As a result:
A: After some time, non-EPFL Internet end-systems cannot reach any EPFL destination
Question: After some time refers to the expiration date of cached data of it?
4) You access a web page that consists of 1 HTML file and 3 pictures, all stored on the same server. Suppose your browser uses a single non-persistent connection, and that DNS resolution has already been completed. What is the minimum number of round-trip-times needed to display the web page?
A: 8 RTTs
Question: My initial thought was 5 (1 RTT for TCP connection and then 4 for the HTTP requests). Is it 8, because TCP needs to establish contact before every new request?
Thank you in advance!
