DNS and HTTP from Both Sides

By the end of this lesson you can read a DNS lookup with dig, read a web server's reply with curl -I, see which ports a server is listening on with ss -tln, explain what 127.0.0.1 means, and read one line of a web server's access log. There is no lab in this lesson: every command is shown together with the exact result it prints, so you can read along. You will look from two machines on one lab network: the client secfund at 10.0.0.5, and the web server web01 at 10.0.0.20. The prompt tells you which machine you are on.