The password for the next level can be retrieved by submitting the password of the current level to port 30000 on localhost.
ssh, telnet, nc, openssl, s_client, nmap
How the Internet works in 5 minutes (YouTube) (Not completely accurate, but good enough for beginners) IP Addresses IP Address on Wikipedia Localhost on Wikipedia Ports Port (computer networking) on Wikipedia
ssh -p 2220 [email protected]
MU4VWeTyJk8ROof1qqmcBPaLh7lDCPvS
telnet localhost 30000
echo MU4VWeTyJk8ROof1qqmcBPaLh7lDCPvS | nc 127.1.0.0 30000
8xCjnmgoKbGLhHFAZlGE5Tmu4M2tKJQo