- 21 FTP
- 22 SSH
- 23 TELNET
- 25 SMTP
- 53 DNS
- 80 HTTP
Port Checker is an online tool to scan your IP address and check if port forwarding is open or blocked by firewall.
If you are encountering connection issue on your server then you may wish to verify port forwarding which tells your router to direct the traffic for port your enter and our tool then verify the success of the process.
Most residential connections commonly have SMTP, 25 and HTTP, 80 port blocked at ISP level to prevent malicious activities.