Quiz — Transport & Ports
Quiz on TCP/UDP and essential port numbers
Module 4 Knowledge Check — apply transport and ports
You multiplexed with ports, told the TCP handshake without firing SYNs at strangers, treated UDP as a different firewall story, and probed only 127.0.0.1. Ten APPLY scenarios. Next: NAT, Firewalls & Routers.
APPLY: A packet is 10.0.2.15:51234 → 1.1.1.1:443 tcp. Which number identifies the service the client wants, and which is ephemeral multiplex?
APPLY: You describe TCP as SYN, then SYN-ACK, then ACK, then a numbered byte stream with retransmission. A classmate wants a raw-socket script against the printer. What is the ethical next step?
APPLY: A stateful firewall allows ESTABLISHED TCP after a handshake but drops "stray" UDP after a short timeout. DNS starts failing while SSH still works. Plausible explanation?
APPLY: ss -tuln shows 127.0.0.1:8080 and 0.0.0.0:22. You join public Wi-Fi. Which bind is the bigger LAN exposure?
APPLY: A ticket says "we opened 3389 to the internet for a vendor." Which service and why do defenders flinch?
APPLY: Match the doors: database you meant to keep local, leftover Java HTTP, mail submission.
APPLY: True or False: python3 -m http.server 8000 --bind 127.0.0.1 plus curl http://127.0.0.1:8000/ is in-scope; nmap of the school /24 is not.
APPLY: Which two statements about this short list are correct? (Select 2)
APPLY: nc -zv 127.0.0.1 8000 succeeds while a python http.server --bind 127.0.0.1 is running, then fails after Ctrl+C. What did you prove?
APPLY: True or False: After Transport & Ports, the next lesson is NAT, Firewalls & Routers — how private addresses and policy at the edge change what those ports mean from the outside.