TCP/IP Secure and Insecure Network Ports

In the world of networking, TCP/IP ports are the doors that allow communication between systems and services. Each port number represents a specific service - some are secure and encrypted, while others remain vulnerable and open to attacks.

Let’s explore the difference between the two types

Secure TCP/IP Ports​

Secure ports are used for encrypted data transmission, ensuring privacy and authenticity. They use strong encryption protocols like SSL/TLS or SSH, protecting your data from eavesdroppers and hackers.

Common Secure Ports​

• Port 443 (HTTPS) - Encrypted web traffic used for secure websites.
• Port 22 (SSH) - Secure shell for encrypted remote administration.
• Port 993 (IMAPS) - Secure mail access with SSL/TLS encryption.
• Port 465 (SMTPS) - Encrypted SMTP mail delivery.
• Port 995 (POP3S) - Secure POP3 mail retrieval.

Example command to check secure port status:

sudo nmap -p 22,443 --open yourdomain.com

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Insecure TCP/IP Ports​

Insecure ports are communication channels that lack encryption, making them easy targets for hackers. Attackers often scan these ports to exploit weaknesses, intercept data, or gain unauthorized access.

Common Insecure Ports​

• Port 80 (HTTP) - Unencrypted web communication vulnerable to sniffing.
• Port 21 (FTP) - Transfers files in plain text (use SFTP instead).
• Port 23 (Telnet) - Unsecured remote login, replaced by SSH.
• Port 110 (POP3) - Unencrypted mail retrieval.
• Port 25 (SMTP) - Plain text email transfer.

Try scanning your system to identify risky open ports

sudo nmap -sS -p 21,23,25,80,110 target_ip

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How to Secure Your Network Ports​

1. Use firewalls to restrict access to unnecessary ports.
2. Close unused ports on routers and servers.
3. Switch to encrypted alternatives (e.g., HTTPS instead of HTTP).
4. Monitor network activity using tools like Wireshark or netstat.
5. Regularly perform vulnerability scans with trusted scanners such as:
   • HackerTarget Port Scan
   • Ping.eu Port Checker
   • ViewDNS Port Scanner

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Final Thoughts​

Understanding and managing secure vs insecure TCP/IP ports is a must for maintaining a robust network defense. By closing risky ports and using encryption-based protocols, you can drastically reduce your system’s exposure to cyber threats.