Application Layer Protocols (HTTP, DHCP, Telnet, SSH) Flashcards
Q: What is the client-server model?
A: A network model where a central server provides services and clients request those services.
Q: What is the peer-to-peer (P2P) model?
A: A network model where each device (peer) can act as both a client and a server.
Q: Give examples of P2P applications.
A: BitTorrent, blockchain-based systems.
Q: What is HTTP?
A: A protocol used to transfer web resources such as HTML documents.
Q: What are the main parts of an HTTP request?
A: Request line (method, path, version), headers, optional body.
Q: Name three common HTTP methods.
A: GET (retrieve data), POST (submit data), DELETE (remove data).
Q: What does an HTTP response include?
A: Status line (version, status code, message), headers, and a body (e.g., HTML page).
Q: What are common HTTP response codes?
A: 200 OK, 301 Moved Permanently, 404 Not Found.
Q: How is HTTP version 2 (HTTP/2) different from HTTP/1.1?
A: Supports multiplexing, header compression, and reduced latency.
Q: What protocol does HTTP/3 use instead of TCP?
A: QUIC – a UDP-based protocol with built-in encryption.
Q: What does HTTPS provide that HTTP does not?
A: Server authentication and encrypted data transfer.
Q: What technology underpins HTTPS?
A: TLS (Transport Layer Security).
Q: What is DHCP used for?
A: Automatically assigns IP addresses and other network settings to devices.
Q: What are key benefits of DHCP?
A: Centralized, automated IP management; prevents IP conflicts.
Q: What information can DHCP provide?
A: IP address, subnet mask, default gateway, DNS server.
Q: What is Telnet?
A: A protocol for remote terminal access that sends data in plaintext — insecure.
Q: What is SSH?
A: A secure alternative to Telnet that encrypts data and ensures authentication.
Q: What is the syntax to connect via SSH?
A: ssh [username]@[hostname or IP address]
Q: What is DNS?
A: The Domain Name System translates human-readable domain names into IP addresses.
Q: Why is DNS important?
A: It allows users to access websites using domain names instead of remembering IP addresses.
Q: What is a URL?
A: Uniform Resource Locator – a structured address that specifies the resource location on the Internet.
Q: What are the key components of the DNS hierarchy?
A: Root servers, Top-Level Domain (TLD) servers, and Authoritative name servers.
Q: What is the function of a root DNS server?
A: Acts as the first contact when a DNS resolver cannot resolve a name.
Q: What is an authoritative DNS server?
A: It holds the actual records for a domain and provides final responses to queries.
