SSHPORT 22SSH allows humans and bots to log into remote servers.
TNETPORT 23TELNET is an older protocol for logging into remote machines.
FTPPORT 21FTP is a legacy protocol, allowing files to be accessed remotely.
RDPPORT 3389RDP supports logging in with a virtual desktop (usually on Windows).
SMBPORT 445SMB is a remote file access protocol, introduced by Windows.
SIPPORT 5060SIP allows humans and bots to make phone calls.
HTTPPORT 80HTTP is the web protocol â bots probe it for exploitable apps and known vulnerabilities.
SMTPPORT 25/587SMTP is the email protocol â spam bots try to hijack this server as a mail relay.