Top 3 Tcp Interview Questions
Browse 3 real-world technical and behavioral interview questions about Tcp. Review scenarios, edge cases, and architectural best practices.
Your application cannot reach a service that should be up. Walk me through diagnosing it from the shell.
Work up the layers and let each command eliminate a class of cause: resolve the name, check the route, see whether anything is listening, then decide from the failure mode whether packets are being refused, silently dropped, or answered by something that never replies.
When would you choose UDP over TCP, given that TCP is reliable and UDP is not?
TCP guarantees an ordered byte stream and pays for it with head-of-line blocking and retransmissions that arrive too late to be useful. UDP is right when a late packet is worthless, when you need multicast, or when you intend to build your own reliability with different trade-offs.
Walk me through everything that happens when you type a URL into the browser and press enter.
The browser checks its caches, resolves the hostname through browser, OS and resolver caches, opens a TCP connection, completes a TLS handshake, sends the request, then parses the streamed response. QUIC fuses transport and crypto setup into one round trip and stops one lost packet stalling every stream.