Networking Interview Q&A
Q: TCP vs UDP?
TCP: reliable, ordered, connection-oriented (3-way handshake), slower. UDP: unreliable, unordered, connectionless, faster. TCP for: HTTP, SSH, databases. UDP for: DNS, video streaming, gaming.
Q: How does DNS resolution work?
Browser → OS cache → Recursive resolver (ISP) → Root nameserver (knows .com TLD) → TLD nameserver → Authoritative nameserver → Returns IP.
Q: What is a subnet and CIDR?
Subnet: subdivision of IP network. CIDR: Classless Inter-Domain Routing notation. 10.0.0.0/24 = 256 addresses (10.0.0.0–10.0.0.255). /16 = 65,536 addresses. /32 = single host.
Q: OSI model layers?
7-Application, 6-Presentation, 5-Session, 4-Transport (TCP/UDP), 3-Network (IP), 2-Data Link (Ethernet), 1-Physical. Remember: "All People Seem To Need Data Processing."
Additional Reference
This topic has detailed content in adjacent sections. Check Overview for architecture, Fundamentals for core concepts, and Cheatsheets for quick command reference. Cross-reference with related topics in the same academy for complete understanding.