Computer Networks Interview Questions

OSI and TCP/IP, TCP vs UDP, handshakes, DNS, HTTP versions, TLS, subnetting, NAT, and what happens when you type a URL.

30 questions in this section

OSI Model vs TCP/IP Model: Layers and Where Each Protocol Lives (Beginner)
MAC Address vs IP Address (Beginner)
Hub vs Switch vs Router (Beginner)
Ports and Sockets Explained (Beginner)
IPv4 Addressing: Classes, Private Ranges and Special Addresses (Beginner)
Subnetting and CIDR with a Worked Example (Intermediate)
IPv4 vs IPv6 (Beginner)
NAT and PAT: How Private Networks Reach the Internet (Intermediate)
ARP: How an IP Address Is Resolved to a MAC Address (Intermediate)
DHCP and the DORA Process (Intermediate)
Routing: Static vs Dynamic, Distance Vector vs Link State (Intermediate)
ICMP, Ping and Traceroute (Beginner)
TCP vs UDP (Beginner)
TCP Three-Way Handshake and Four-Way Connection Teardown (Intermediate)
TCP TIME_WAIT State: Why It Exists and How to Handle It (Advanced)
How TCP Achieves Reliable Delivery (Advanced)
Flow Control vs Congestion Control in TCP (Advanced)
DNS Resolution: Recursive vs Iterative Queries (Intermediate)
DNS Record Types and TTL Caching (Intermediate)
HTTP Methods and Status Codes (Beginner)
Cookies vs Sessions (and Tokens) (Beginner)
HTTP/1.1 vs HTTP/2 vs HTTP/3 (QUIC) (Advanced)
HTTPS and the TLS Handshake (Advanced)
Symmetric vs Asymmetric Encryption and Digital Certificates (Intermediate)
WebSockets vs Polling vs Server-Sent Events (Intermediate)
How a CDN Works (Intermediate)
Load Balancer vs Reverse Proxy (Intermediate)
Firewall Basics: Packet Filtering, Stateful Inspection and WAF (Intermediate)
What Happens When You Type a URL in the Browser (Advanced)
Debugging: Site Unreachable, Connection Refused vs Timed Out vs Slow (Advanced)

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