Networking Fundamentals Questions

Foundational knowledge of how networks operate and how to reason about network behavior. Core concepts include the TCP IP model and common protocols such as IP, TCP, UDP, DNS, and DHCP; subnetting and address allocation; routing and switching fundamentals; VLANs and layer two segmentation; NAT and private addressing; firewall and access control behavior; VPNs and tunneling; ports and application layer protocols. Candidates should also be able to apply these fundamentals to troubleshoot connectivity and performance issues at a conceptual level, explain the TCP three way handshake, congestion and retransmission causes, and reason about where problems occur in the stack.