The following are the frequently used well known port numbers in linux
servers used by various daemon services and applications. You may want
to configure your firewall accordingly to restrict services running on
your server by blocking the desired ports.
Port 21 –> TCP –> FTP (File Transfer
Protocol)
Port 22 –> TCP/UDP –> SSH (ssh,scp
copy or sftp)
Port 23 –> TCP/UDP –> Telnet
Port 25 –> TCP/UDP –> SMTP (for sending
outgoing emails)
Port 43 –> TCP –> WHOIS function
Port 53 –> TCP/UDP –> DNS Server
(DNS lookup uses UDP and Zone transfers use TCP)
Port 70 –> TCP –> Gopher Protocol
Port 79 –> TCP –> Finger protocol
Port 110 –> TCP –> POP3 (for receiving
email)
Port 113 -> ident tcp outbound
Port 115 --> Secure File transfer protocol
Port 119 –> TCP –> NNTP (Network
News Transfer Protocol)
Port 143 –> TCP/UDP –> IMAP4 Protocol
(for email service)
Port 194 –> TCP –> IRC
Port 389 –> TCP/UDP –> LDAP (light
weight directory access)
Port 443 –> TCP –> Secure HTTP over
SSL (https)
Port 465 –> TCP –> Secure SMTP (email)
using SSL
Port 783 -> TCP -> SpamAssassin spamd daemon
Port 990 –> TCP/UDP –> Secure FTP
using SSL
Port 993 –> TCP –> Secure IMAP protocol
over SSL (for emails)
Port 4664 -> Google desktop search port
Port 1433 –> TCP/UDP –> Microsoft
SQL server port
Port 2082 –> TCP –> CPanel default
port
Port 2083 –> TCP –> CPanel over SSL
Port 2086 –> TCP –> CPanel Webhost
Manager (default)
Port 2087 –> TCP –> CPanel Webhost
Manager (with https)
Port 2089 -> TCP -> Cpanel license tcp outbound
Port 2095 –> TCP –> CPanel Webmail
Port 2096 –> TCP –> Cpanel secure
webmail over SSL
Port 2222 –> TCP –> DirectAdmin Server
Control Panel
Port 3306 –> TCP/UDP –> MySQL Database
Server
Port 4643 –> TCP –> Virtuosso Power
Panel
Port 5432 –> TCP –> PostgreSQL Database
Server
Port 5224 -> plesk-license-update (outgoing connection
only)
Port 8443 -> plesk-https
Port 6666 -> chat tcp inbound
Port 8080 –> TCP –> HTTP port (alternative
one for port 80)
Port 8087 –> TCP –> Plesk Control
Panel Port (default)
Port 8443 –> TCP –> Plesk Server
Control Panel over SSL
Port 8880 -> Plesk-http
Port 9080 -> Tomcat
Port 9999 –> TCP –> Urchin Web Analytics
Port 10000 –> TCP –> Webmin Server
Control Panel
Port 19638 –> TCP –> Ensim Server
Control Panel
Port 39270 -> Limewire