A port says something is there. A version says what it is and how old. This set checks that you can ask a service to identify itself and read the answer, and that you know what the version does and does not tell you.
Each one is marked as you go, and the explanation arrives straight after, which is
the part worth reading.
4 questions, marked as you go.
Tasks
These need your own device. Run the command in Termux, then paste what it printed.
The marking looks at what the output means, so spacing, version numbers and
ordering do not matter. If you have not installed anything yet, the
lesson covers the setup.
Ask nmap for the service version
This scans port 8022 on localhost with service detection. Start the Termux SSH server first with sshd so there is something to identify. Paste the whole scan output.
Run this in Termux
On your own device. Nothing on this page executes it. The command runs in
your terminal, and this box only reads what you paste back.
nmap -sV -n -p 8022 localhost
Look for the VERSION column and the line saying service detection was performed. The version shown is whatever OpenSSH that Termux ships.
the table asks for a version as well as a service
service detection actually ran
the port row reports its state
the command actually ran
What a good answer looks like
nmap's usual shape, but with a VERSION column in the table. The row reads the port and protocol, the state, the service and then a version string, such as OpenSSH followed by a number, when the port is open. Below the table comes the line saying service detection was performed, and then the closing summary. The VERSION column is the point of the command: it is the thing a known issue attaches to. If the port is closed, the table still appears with its VERSION heading, but there is no version to read because nothing answered.
Marking your own work
Both halves of this are checked in your browser, with no server involved, so nothing
stops you from pasting output you did not run. The tasks are written so that the
easiest way to pass one is to actually do it and read the result, which is the whole
intention.