Review and Catch Up

Were you able to do all of the assigned reading and watching during the semester? If not, catch up! If so, review a little bit! Here’s the content that was previously assigned. Review now, or read/watch for the first time:

• From the Comer text:
• Chapters 1-7, 12 (skim), 13, 18 (skim), 20, 21, 22 (.1-.12 only), 23 (.1-.6, .15-.19 only), 24-27, 30
• From Jacob Aae Mikkelsen’s online slides:
• Lecture 1 (Intro)
• Lecture 2 (Application layer)
• Lecture 4 (Network layer, IP)
• Lecture 5 (Link layer, Ethernet & ARP, Slides 1-24 only)
• Lecture 3 (Transport layer, UDP & TCP, Slides 1-20, 52-76 important; skim the rest)
• Lecture 8 (Security)
• From YouTube:
• Crash Course Computer Science videos, episodes 28, 29, 30,
• Tom Scott: SQL Injection, XSS, Hashing, How NOT to Store Passwords!, CSRF, Whole Internet attack, Buffer Overflows, Shellshock, Moonpig, The Link That Can Crash Chrome, XSS on Twitter Effective Power Bug, Man in the Middle
• Ashley Williams on Node.js/Rust
• Papers and articles:
• Hobbes’ Internet Timeline
• Cerf and Kahn Paper
• RFCs: 1925, 2119, 3339, 2151, 791, 3631
• Docs: Node.js net, NPM ws, W3C WebSockets, Socket.io
• OWASP Top Ten 2017
• AWS Overview Whitepaper

Also, it would not hurt to read over my answers to all of the homework problems. 🙂

Self Check

Make sure you have successfully met the course learning objectives, by being able to do each of the following:

• Explain the difference between a network and an internet
• Explain what a protocol is
• Explain the purpose of each of the four layers and how they interface with each other
• Explain the functionality and major protocols of the link layer
• Explain the functionality and major protocols of the network layer
• Explain the functionality and major protocols of the transport layer
• Explain the functionality and major protocols of the application layer
• Describe the awesomeness of the Internet’s design and why it works so well
• Talk about the early days of the Internet and how it came to be
• Describe the edge and core of the Internet
• Use ping, traceroute, ip (or ifconfig), nslookup, netstat, and nc, and know what they do
• Describe what a socket is and recite the basic operations of the low level socket API
• Explain how client-server apps differ from P2P apps
• Write TCP-based client-server applications in Java, Python, and JavaScript
• Explain threaded vs. evented servers and the advantages and disadvantages of each
• Describe HTTP request methods GET, PUT, POST, PATCH, DELETE, HEAD, OPTIONS
• Describe HTTP response codes 200, 201, 202, 204, 304, 400-406, 500-503
• Describe the format of HTTP requests and responses
• Write a simple web server in Express
• Access HTTP servers with nc, curl, and programmatically
• Explain the limitations of HTTP and why WebSockets were created
• Write a program with WebSockets
• Describe basic characteristics of wire, fiber, radio, microwave, and satellites, and approximate speeds of different media
• Explain the difference between packet switching and circuit switching
• Explain how packets can be delayed
• Explain the basic ideas behind Ethernet in particular and link layer technologies in general
• Describe the main parts of an Ethernet frame
• Explain the major features of IP
• Work with CIDR notation in IPv4 and IPv6, e.g. find address range for CIDR block
• Simplify or expand IPv6 addresses
• Explain the important differences between IPv4 and IPv6
• Know what loopback, anycast, and broadcast addresses are
• Know how IP routing tables work and why netmasks are so awesome
• Explain how ARP works and why it (or something like it) is needed
• Explain the important differences between UDP and TCP
• Describe the important fields of a TCP segment
• Explain the TCP handshake for establishing a connection
• Explain the TCP handshake for closing a connection
• Explain TCP windowing
• Explain how NAT works and why it (or something like it) is needed for IPv4
• Explain the major dimensions of the study of security
• Explain a few things attackers can do
• Explain the main players in a traditional cryptosystem
• Explain why cryptography must be key-based on not rely on algorithm secrecy
• Explain the (many!) differences between secret key and public key cryptography
• Describe Diffie-Helmann key exchange
• Describe how RSA works (mathematically)
• Explain both hashing and digital signatures, and how they differ
• Use Java, Python, and JavaScript libraries to encrypt and decrypt data streams
• Explain buffer overflow, injection, XSS, and CSRF attacks
• Talk about the password storage (what could go wrong) and token authentication
• Describe what cloud computing is and recite several advantages
• Use IAM, S3, EC2, and Lambda in the AWS Console and from the AWS CLI

Practice Problems

Get more practice. Select a few problems from this problem set or end-of-chapter problems from a networking textbook that appear related to the material we covered in class.

Logistics

Know what to expect!

• The exam will take place on 2019-05-07.
• There will be approximately 10 questions.
• Open notes, computer, etc., closed other-people.
• Because of open sources, questions will focus on what you can do, not what you can look up.
• No AWS questions.
• Answer all questions on paper.