You’re in a tiny room at Googamazbook and the interviewer comes in, says hi (if you’re lucky), presents themselves (they’re really into doing you a favor) and then starts asking questions. The easy one comes first:
What happens when you run telnet www.brainware.ro 80 ? Please go on through all the layers.
Warmed up from the systems interview, you start talking about /etc/hosts and /etc/resolv.conf: name resolution and then the actual connection to the http port. If your knowledge stops here, please do go on reading this text. Or just do go on, maybe I forgot something.
1. Name Resolution
The name resolution protocol is performed by sending an UDP packet to each resolver found in /etc/resolv.conf. The UDP packet has a small header containing: