Install the nmap package. Create a bogus user with a simple password (and don’t
ID: 3820103 • Letter: I
Question
Install the nmap package.
Create a bogus user with a simple password (and don’t forget it…).
bogususer / supersecurepassword387 for example.
Install and configure an FTP server. Instructions here.Make sure bogususer can login to ftp from your Mac.
Command + k in the Finder to open a new connection: ftp://[your centos os]
Show Kevin your ability to login for points.
Task 1: Fun Commands
netstat
What is the netstat command to see what sockets are listening on TCP (specifically IPv4)?
What services are currently listening?
Are there any services that are strictly locally bound? How can you tell which ones are locally bound or not?
nmap
What is the command to scan ports 20-25 on localhost only?
What ports/services are open on your CentOS?
What OS does nmap think you’re running?
tcpdump
sudo tcpdump -i [WHICH INTERFACE?] -nn port [WHICH PORT DOES FTP RUN ON?] -w tcpdump.out
Now login to your ftp server from your mac again.
sudo tcpdump -r tcpdump.out -XX
Find your login information.
Reflect on the lesson here (how is it possible, how can you prevent it, is it really that insecure?)
Task 2: Firewall Action
Use the firewall-cmd to drop all incoming pings.
Try to ping your CentOS machine from your Mac. It should not work.
Write down the command.
Show me it working.
Remove the previous rule created (the one from question 1)
Write down the command.
Task 3: Understanding Traceroute
Find a working traceroute server from this page.
Run a traceroute from one of the links.
It will traceroute from its location to our school.
Now run a traceroute from the command line to the host that you used from the link.
Include the output in a text file for both.
Why may the traceroutes be different?
What do the asterisks mean in a traceroute?
Do you see cenic.net anywhere in the traceroute? Goto their website.
What is the role of an “Internet backbone” company?
Explanation / Answer
I think this question is for practising in the lab or one's own laptop/desktop. And the instructions to set the FTP server is also not provided here..
I request you to kindly set up the server as given in the instructions manual.
If you have any specific questions about netstat and other stuff, you can ask the same as seperate question.