Port numbers quiz
Every CompTIA exam — A+, Network+, Security+ — expects you to know your ports cold. This endless drill covers the 35 ports they actually test, in both directions: name the port, and name the protocol. No signup, no limit.
The full list
| Port | Protocol | Transport |
|---|---|---|
| 20/21 | FTP | TCP |
| 22 | SSH/SCP/SFTP | TCP |
| 23 | Telnet | TCP |
| 25 | SMTP | TCP |
| 49 | TACACS+ | TCP |
| 53 | DNS | TCP/UDP |
| 67/68 | DHCP | UDP |
| 69 | TFTP | UDP |
| 80 | HTTP | TCP |
| 88 | Kerberos | TCP/UDP |
| 110 | POP3 | TCP |
| 119 | NNTP | TCP |
| 123 | NTP | UDP |
| 135 | RPC/DCOM | TCP |
| 137-139 | NetBIOS | TCP/UDP |
| 143 | IMAP | TCP |
| 161/162 | SNMP | UDP |
| 389 | LDAP | TCP |
| 443 | HTTPS | TCP |
| 445 | SMB | TCP |
| 465 | SMTPS | TCP |
| 514 | Syslog | UDP |
| 587 | SMTP (STARTTLS) | TCP |
| 636 | LDAPS | TCP |
| 993 | IMAPS | TCP |
| 995 | POP3S | TCP |
| 1433 | MS-SQL | TCP |
| 1521 | Oracle SQL | TCP |
| 1645/1646 | RADIUS | UDP |
| 1812/1813 | RADIUS | UDP |
| 3306 | MySQL | TCP |
| 3389 | RDP | TCP |
| 5060/5061 | SIP | TCP/UDP |
| 6514 | Syslog TLS | TCP |
| 8080 | HTTP Alt | TCP |
Ports are the easy 5%
The rest of the exam is scenarios. Take the free 25-question diagnostic to see how ready you actually are — and get a daily plan for everything else.
Take the free diagnosticFrequently asked questions
Which port numbers do I need to memorize for CompTIA exams?
The core set is about 35 ports: the classics (SSH 22, DNS 53, HTTP 80, HTTPS 443, RDP 3389), the email family (SMTP 25/587, POP3 110/995, IMAP 143/993), and infrastructure protocols (DHCP 67/68, SNMP 161/162, LDAP 389/636). Network+ leans hardest on ports; Security+ loves asking which secure variant replaces which insecure one.
What's the best way to memorize port numbers?
Short, frequent drills beat one long cram. Do 10–20 questions here daily, and pay attention to the pairs — secure vs insecure versions (HTTP 80 → HTTPS 443, LDAP 389 → LDAPS 636, Telnet 23 → SSH 22) are the most-tested pattern. Spaced repetition automates the schedule: miss a port and it comes back right before you'd forget it.
Do I need to know TCP vs UDP for each port?
Yes — especially for Network+. The commonly tested UDP ones: DHCP (67/68), TFTP (69), NTP (123), SNMP (161/162), and syslog (514). DNS famously uses both: UDP for queries, TCP for zone transfers.