Networking - Important Ports
TECH101 PORT CHEAT SHEET | |||
Port number | Service name | Transport protocol | Description |
7 | Echo | TCP, UDP | Echo service (Ping- ECMP Echo Request) |
21 | FTP | TCP, UDP, SCTP | File Transfer Protocol command control |
22 | SSH/SCP/SFTP | TCP, UDP, SCTP | Secure Shell, secure logins, file transfers (scp, sftp), and port forwarding |
25 | SMTP | TCP | Simple Mail Transfer Protocol, used for email routing between mail servers |
53 | DNS | TCP, UDP | Domain Name System name resolver |
67 | DHCP/BOOTP | UDP | Dynamic Host Configuration Protocol and its predecessor Bootstrap Protocol Server; server port |
68 | DHCP/BOOTP | UDP | Dynamic Host Configuration Protocol and its predecessor Bootstrap Protocol Server; client port |
69 | TFTP | UDP | Trivial File Transfer Protocol |
80 | HTTP | TCP, UDP, SCTP | Hypertext Transfer Protocol (HTTP) uses TCP in versions 1.x and 2. HTTP/3 uses QUIC, a transport protocol on top of UDP |
88 | Kerberos | TCP, UDP | Network authentication system |
110 | POP3 | TCP | Post Office Protocol, version 3 (POP3) |
123 | NTP | UDP | Network Time Protocol |
143 | IMAP | TCP, UDP | Internet Message Access Protocol (IMAP), management of electronic mail messages on a server |
389 | LDAP | TCP, UDP | Lightweight directory access protocol |
443 | HTTPS (HTTP over TLS) | TCP, UDP, SCTP | Hypertext Transfer Protocol Secure (HTTPS) uses TCP in versions 1.x and 2. HTTP/3 uses QUIC, a transport protocol on top of UDP. |
464 | Kerberos | TCP, UDP | For password settings on Kerberos |
465 | SMTP over TLS/SSL, SSM | TCP | Authenticated SMTP over TLS/SSL (SMTPS), URL Rendezvous Directory for Cisco’s Source Specific Multicast protocol (SSM) |
500 | IPSec / ISAKMP / IKE | UDP | Internet Protocol Security / Internet Security Association and Key Management Protocol / Internet Key Exchange |
520 | RIP | UDP | Routing Information Protocol, used to find the optimal path between source and destination networks |
587 | SMTP | TCP | For email message submission via SMTP |
636 | LDAP over TLS/SSL | TCP, UDP | Lightweight Directory Access Protocol over TLS/SSL |
993 | IMAP over SSL (IMAPS) | TCP | Internet Message Access Protocol over TLS/SSL |
995 | POP3 over SSL (POP3S) | TCP, UDP | Post Office Protocol 3 over TLS/SSL |
1812 | RADIUS | UDP | RADIUS server authentication and authorization |
1813 | RADIUS | UDP | RADIUS server accounting |
3306 | MySQL | TCP | MySQL database system  |