Packet Capture (Packet Sniffing)

Some server OSs have services running by default, such as HTTP (port 80) and FTP (ports 20 & 21) which should be removed when systems are installed. (The command line network utility . netstat. can be used to check which services are running on the same host). Eve. Internet. Bob. DMZ. Scanning … Port 20 - closed Port 21 - closed Port 22 ... ................
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