|
Server ports or Internet ports are network connections that are used for the transmission of information between a web server and a web client and help route traffic to specific applications and specific machines. The internet Transmission Control Protocol (TCP) designates 65,535 numbered ports. Many of the ports are reserved for specific protocols, with the lower number ports used most often. Two of the most used ports are 80 for HTTP and 443 for HTTPSecure. Other common ones are 20 and 21 for File Transfer Protocol (FTP), 25 and 587 for Simple Mail Transfer Protocol (SMTP), 53 for Domain Name System (DNS) and 3389 for Microsoft Remote Desktop Services (RDS).
BlueWorldData "IP Port Scan" can tell you the status of ports for a specific IP address (and for the other IP addresses in that same address block of 255 IP addresses). For example, to see if Google has an open HTTP port, enter Google IP address of "142.250.176.206" in the "IP address" field of "IP Scan" and then enter "80" in the "Ports" field. Clicking on "SUBMIT" will then display whether Port "80" is "Open" ("true") or not ("false") for the address block of 255 IP addresses beginning with "142.250.176.1" and ending with "142.250.176.255". All 255 IP addresses are polled. Only the IP addresses that respond with a "true" or "false" are listed. IP addresses not listed did not respond and are considered to be "unreachable". Check boxes in the IP/Port Scan command provide a quick way to enter your own IP address and the two most common ports "80,443". To stop customers from hosting their own FTP servers and websites, some Internet service providers (ISPs) block ports, like 21 or 80. Hackers scan ports looking for network vulnerabilities so some ISPs will block other ports for security reasons. For better performance, no more than 10 ports should be entered for each scan. Port numbers should be between 1 and 65535. All other numbers will be ignored. |