ECE8843 Homework Assignment 3 (HW-3) (v.1.0, 10/3/04) Due before 8 am Friday Oct. 8. Video students on Oct 22. Instructions. Copy this document from the Web Page, or save it from your email program, as a "text" file. Edit it in a word processor to add the answers into the square brackets after each question. Save it as a "text" file, and email it back to me: (john.copeland@ece.gatech.edu). Email the completed document as the body of a message (not as an attached document) with the Subject exactly as "HW-3" (4 characters). Please send questions or comments in a separate message, with a different Subject (e.g., "Question on HW-3"). Mail with the correct subject will be automatically filtered into the homework grading program. Including quotes or extra spaces may prevent your homework submission from being automatically graded. I will not accept paper returns. If you can not complete the assignment on time, tell me why and turn it in as soon as possible for partial credit. Remember, home work grades count as 10% of the final grade. Your return will be graded by a computer program that looks for your answers between square brackets. Please do not add or delete square brackets (or the ***???*** flags). The format and units of answers should be those indicated in the problem (e.g., a letter, a group of letters, or a number). Each question counts equally. Each answer within a question counts equally, but the value depends on the number of answers within the question. All letters after a number are ignored so do not use letter multipliers (e.g., M, m, k, etc.). If the answer is a percentage, the format may be 0.52 or 52% (52 is assumed to mean 5200%). You must include the % or use a decimal fraction. We are learning in this course how computers talk securely to each other. At present there must always be a set of rules (protocol or formatting rules) that govern the data sent so that a protocol layer or application can understand the messages it receives. In a protocol PDU every bit has to be correct and in exactly the right order. The homework submission protocol is far more "free form", but it is still far from accepting as wide a range of formatting as a human being. See http://www.csc.gatech.edu/copeland/jac/8843/hw_tips.html, "Tips on Submitting HW" for more information. --------- ( You may delete everything above this line) ------------------ ***START_HW*** [ ]-NAME Enter your name (form: last, first ). [ ]-PRISM Enter your Prism or "mail" account code (form: "gtXNNNA" where "N" is a number, "A" is a letter, and X is either. Do not include "@prism.gatech.edu"). [ ]-EMAIL Enter the email address ("account@server") where you would like to receive your graded homework and other class information (including quiz grades). If on Prism or "mail.gatech.edu", leave blank. The following questions are about the material covered in Chapter 6 and slide set "06-IP Networks.ppt". IP call setup. When you startup your PC and browser and type "http://www.weather.com", what are the four steps that have to take place before the first Web page is downloaded. Answers should be from this list: Enet, IP, UDP, TCP, ICMP, DNS, Web, ARP, BOOTP, Host, Router, Switch. The first answer is a layer 1, 2, or 3 protocol. In questions 1 and 3 the second is a type of message. #1. A [ ] [ ] broadcast message is sent out to find the [ ] address for the [ ] server. #2. A [ ] request for the 32-bit [ ] address of "www.weather.com" is sent to the [ ] server. #3. A [ ] [ ] message is sent out to find the [ ] address for the [ ] server. #4. A [ ] SYN packet is sent to [ ] address of www.weather.com. #5. Since the PC is not on the same LAN as www.weather.com, the destination Enet (Ethernet) address is that of the [ ]. ---- IPsec. Name the two services. The answers are two or three letters long. #6. [ ] provides authentication for packets. #7. [ ] provides encryption for packets. Both services have two modes of operation. Both start with "T". #8. [ ] mode provides end-to-end authentication and/or encryption from host to host. #9. [ ] mode provides LAN-to-LAN or Host-to-LAN service (LAN = local area network). #10. [ ] mode is used to form a VPN (virtual private network). #11. [ ] mode can provide TLS (transport level security). ***END_HW*** (do not delete preceding flag) (1.0 - email)