Commonly Used Port Numbers

Commonly Used Port Numbers From time to time you may want to test a protocol or service from the command line. To do that, you may need to know the standard port number for that protocol. For example, you might want to verify that your SMTP server is accessible from the Internet. Testing the connection with a standard mail client might mean creating a new mail profile, which is a bother. Moreover, if the connection fails, you might not be able to see where or why it failed. By connecting with a terminal program to a specific port, you can manually send SMTP commands and verify the responses. Below is a list of common protocols and their more-or-less "standard" port numbers. SMTP: Port Telnet: Port 23 FTP: Port 21 25 HTTP: Port NNTP: Port POP3: Port 110 80 119 TFTP: Port Gopher: rtelnet: Port 107 69 Port 70 Whois: Port IRC: Port Finger: Port 79 43 194 SNMP: Port UUCP: Port LDAP: Port 389 161 540 Terminal SQL Server: POP SSL: Services/RDP: Port Port 1433 Port 995 3389 The complete list of standard port numbers may be found in RFC1700: http://www.faqs.org/rfcs/rfc1700.html