Whenever we use TCP/IP connection, we always require default port numbers. Now the question is:
What are default port numbers ?
It is a well known service, used to identify the sender and receiver messages such as NFS Server, Web Server, Mail Server, FTP Server, etc. These servers are using default port numbers.
The range of port numbers is from to 65535.
Some default port numbers are as follows:
| PORT | NAME | Description |
| 22 | SSH | Secure shell |
| 20 | FTP DATA | File Transfer Protocol - Transferring FTP data |
| 21 | FTP Control | Starting FTP Connection |
| 23 | Telnet | For remote administration |
| 25 | SMTP | Send mail Transfer protocol |
| 53 | DNS | Domain name system |
| 67 | Bootp | Bootstrap protocol (DHCP - Client to Server Communication) |
| 68 | DHCP | Dynamic Host Configuration Protocol ( Server to client Communication ) |
| 80 | HTTP/WWW | Hyper Text Transfer Protocol - APACHE |
| 110 | POP3 | Post Office Protocol - Mail Delivery Agent |
| 123 | NTP | Network Time Protocol - |
| 139 | SMB | SAMBA Server - ( smbd ) |
| 143 | IMAP | Internet Message Access Protocol |
| 161 | SNMP | Simple Network Management Protocol - network Monitoring |
| 389 | LDAP | Lightweight Directory Access Protocol |
| 443 | HTTPS | HTTP + SSL - Secure web access |
| 990 | FTPS | FTP Secure |
| 2049 | NFS | Network File System |
| 3306 | MYSQL | Mysql Database |