Ports, Protocols, Purpose, and Encrypted Alternatives

My first time boarding the yellow buses in Lagos State wasn't a funny one. I took a bus from Lekki Phase 1 to Ajah. As a Yoruba girl who had stayed in Port Harcourt and was just arriving in Lagos, my first instinct wasn't to use the popular "owa" to indicate that I wanted to get off. Using the word "highlight" wasn't an option either, as Twitter stories had taught me that people might look at me strangely. So, I used the usual "dropping" word, as I was used to in Port Harcourt, and the drivers there clearly understood. Ladies and gentlemen, the driver carried me past my destination. The other passengers told me I should have used "owa" and mentioned the exact destination. Trust me, I have learned my lesson.

In this story, "ports" are like bus stops, specific locations where you need to signal your intention to stop. Just as different bus stops have specific names ("Lekki Phase 1," "Ajah"), ports have specific numbers (like 80, and 21). The "protocols" are the methods of communication, how you signal to the driver. In Port Harcourt, I used "dropping," similar to how protocols like HTTP or FTP have specific ways to communicate. In Lagos, the expected protocol was "owa + exact destination," just as HTTP and FTP, respectively.

What's your own way of communicating with conductors or drivers to stop you at your destination?

In this post, we will look into what Ports and Protocols are, the Purposes of common ports and their Encrypted Alternatives

Let's Get Right Into It!!!

What are Ports/ Port Numbers?

A port, often known as a port number, is a number allocated to identify a connection endpoint and route data to a service. Ports guarantee that when data arrives on a device, it is sent to the right service/protocol.

Port numbers range from 0 to 65535, with 0-1023 being well-known.

What are Protocols?

A protocol is a way for computers or devices connected to a network to communicate with one another. It outlines the rules or procedures for transmitting data.

Simply put, they are the common language that computers speak.

Now, let's go through common port numbers, protocols, and their encrypted/ secure alternatives.

Port Number	Protocol	Protocol Type	Purpose	Secure Alternative Port Number	Secure Alternative Protocol
Port 20/21	FTP (File Transfer Protocol)	TCP	Transfer files between client and server(where port 20 is for data connection, and port 21 is used for control connection)	Port 989/990	FTPS(FileFile Transfer Protocol Secure)
Port 23	Telnet	TCP	Remote login and command execution	Port 22	SSH(Secure Shell)
Port 25	SMTP (Simple Mail Transfer Protocol)	TCP	Sending emails	Port 465	SMTPS (Simple Mail Transfer Protocol Secure)
Port 53	DNS (Domain Name System)	TCP/UDP	Resolve domain names to IP addresses	DoH- Port 443 DoT- Port 853	DNS over HTTPS (DoH) or DNS over TLS (DoT)
Port 67/68	DHCP (Dynamic Host Configuration Protocol)	UDP	Assign IP addresses to devices on a network	N/A	N/A
Port 69	TFTP (Trivial File Transfer Protocol)	UDP	Simple, unsecure file transfers	N/A	N/A
Port 80	HTTP (Hypertext Transfer Protocol)	TCP	Transmitting web pages on the internet	Port 443	HTTPS(Hypertext transfer protocol secure)
Port 110	POP3 (Post Office Protocol)	TCP	Retrieve and manage emails from a mail server	Port 995	POP3S(Post Office Protocol version 3)/ POP3 over TLS
Port 123	NTP (Network Time Protocol)	UDP	Synchronize clocks over a network	N/A	N/A
Port 137	NetBIOS Name Service	UDP	Name resolution in a LAN	N/A	N/A
Port 143	IMAP (Internet Message Access Protocol)	TCP	Retrieve and manage emails from a mail server	Port 993	IMAPS
Port 161/162	SNMP (Simple Network Management Protocol)	UDP	Network management and monitoring	Port 161/162	SNMPv3 (it uses its encryption methods)
Port 389	LDAP (Lightweight Directory Access Protocol)	TCP/UDP	Directory services	Port 636	LDAPS
Port 445	SMB (Server Message Block)	TCP	File and printer sharing	Varies	SMB over SSL/TLS
Port 514	Syslog	UDP	System logging	Port 6514	Syslog over TLS
Port 3306	MySQL	TCP	Database services	Uses the same port	MySQL over SSL/TLS
Port 3389	RDP (Remote Desktop Protocol)	TCP	Remote desktop access, where it provides a user with a graphical interface to connect to another computer over a network.	Uses the same port	RDP over SSL/TLS
Port 5060	SIP (Session Initiation Protocol)	TCP/UDP	Voice over IP (VoIP)	Port 5061	SIPS

Common port numbers, protocols, and their encrypted/ secure alternatives

Conclusions

Knowing the ports and protocols in your networks is one of the first steps in identifying potential vulnerabilities and understanding how to secure your systems.