The essential network ports every IT pro needs at their fingertips: HTTP/HTTPS, DNS, DHCP, SSH, FTP, SMTP, RDP, and more — with port numbers, TCP vs UDP, and what each service actually does. Built for CompTIA A+, Network+, and Security+ exam prep. More free study resources at bytebarhq.com.
|
20/21
|
TCP — FTP (data/control). "FTP is 21, data rides 20"
|
|
22
|
TCP — SSH / SCP / SFTP. Secure remote — the secure 2's
|
|
23
|
TCP — Telnet. Insecure — never use, know why
|
|
25
|
TCP — SMTP. Sending email
|
|
53
|
TCP/UDP — DNS. UDP for lookups, TCP for zone transfers
|
|
67/68
|
UDP — DHCP (server/client). "DHCP gives, 67/68 delivers"
|
|
69
|
UDP — TFTP. Trivial — no auth, PXE boot
|
|
80
|
TCP — HTTP. Unencrypted web
|
|
110
|
TCP — POP3. Downloads email (deletes from server)
|
|
123
|
UDP — NTP. Time sync
|
|
143
|
TCP — IMAP. Email stays on server
|
|
161/162
|
UDP — SNMP (manager/trap). Monitoring
|
|
389
|
TCP/UDP — LDAP. Directory lookups
|
|
443
|
TCP — HTTPS. Encrypted web
|
|
445
|
TCP — SMB/CIFS. Windows file sharing — ransomware loves it
|
|
636
|
TCP — LDAPS. LDAP over TLS
|
|
993
|
TCP — IMAPS. IMAP over TLS
|
|
995
|
TCP — POP3S. POP3 over TLS
|
|
1433
|
TCP — Microsoft SQL. Database default
|
|
3306
|
TCP — MySQL/MariaDB. Database default
|
|
3389
|
TCP — RDP. Windows remote desktop
|
|
5432
|
TCP — PostgreSQL. Database default
|
|
5900
|
TCP — VNC. Remote screen sharing
|
|
Telnet (23)
|
SSH (22)
|
|
FTP (21)
|
SFTP/SCP (22) or FTPS
|
|
HTTP (80)
|
HTTPS (443)
|
|
SNMP v1/v2 (161)
|
SNMP v3 (auth + encryption)
|
|
POP3 (110) / IMAP (143)
|
POP3S (995) / IMAPS (993)
|
|
Send (SMTP)
|
Plain: 25 (587 submission) → Secure: 465 (SMTPS)
|
|
Receive/read
|
Plain: 110 POP3 / 143 IMAP → Secure: 995 / 993
|
No comments yet.
Cheatography n. The art of mapping complex subjects into clear, instantly navigable reference guides.
