Here is a list of common port numbers in linux servers.
[perch_heading title=”Port Numbers”][/perch_heading]
21 => FTP
22 => SSH
23 => Telnet
25 => SMTP Mail Transfer
43 => WHOIS service
53 => name server (DNS)
80 => HTTP (Web server)
110 => POP protocol (for email)
443 => HTTP Secure (SSL for https:// )
995 => POP over SSL/TLS
9999 => Urchin
3306 = > MysQL Server
2082 => CPANEL Default
2083 => CPANEL – Secure/SSL
2086 => CPANEL WHM
2087 => CPANEL WHM – Secure/SSL
2095 => cpanel webmail
2096 => cpanel webmail – secure/SSL
Plesk Control Panel => 8443
DirectAdmin Control Panel => 2222
Webmin Control Panel => 10000
[perch_heading title=”TCP/UDP Protocol”][/perch_heading]
20 & 21 TCP FTP
22 TCP SSH
23 TCP Telnet
25 TCP SMTP
53 TCP & UDP DNS
67 UDP DHCP
69 UDP TFTP
80 TCP HTTP
88 TCP Kerberos
109 & 110 TCP POPv2 & POPv3
111 TCP & UDP Port Mapper
113 TCP auth/ident
119 TCP NNTP
123 UDP NTP
137 UDP NetBIOS Name Service
138 UDP NetBIOS Datagram
139 TCP NetBIOS Session
143 TCP IMAP 2
161 UDP SNMP
177 UDP XDMCP
220 TCP IMAP 3
389 TCP LDAP
443 TCP HTTPS
445 TCP Microsoft DS
514 UDP Syslog
515 TCP Spooler
636 TCP LDAPS
749 TCP Kerberos Admin
5800-5899 TCP VNC via HTTP
5900 TCP VNC
6000-6099 TCP X (X.org-X11, XFree86)