easyMultiple Choice
220-1201 Practice Question: A user cannot connect to a remote server using RDP
A user cannot connect to a remote server using RDP. The network team confirms that the firewall allows outbound traffic on all ports. Which port is typically used for RDP and should be verified on the server side?
⚠ Common exam trap
The A+ exam often tests default port numbers for common protocols, and the trap here is that candidates confuse RDP with VNC (port 5900) or SSH (port 22), especially when the question mentions 'remote server' without specifying the protocol.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Port 3389
RDP (Remote Desktop Protocol) uses TCP port 3389 by default. Since the firewall allows outbound traffic on all ports, the issue is likely that the server-side firewall or the RDP service is not listening on port 3389, or the port is blocked inbound on the server's firewall. Verifying that port 3389 is open and the RDP service is running on the server is the correct next step.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Port 22
Why it's wrong here
Port 22 carries SSH, not RDP, so checking it does not confirm whether the Remote Desktop listener is reachable. It is tempting because 22 is the standard secure remote-administration port, and it would be correct for a Linux SSH session, but RDP uses TCP 3389, so this verification targets the wrong service.
- ✓
Port 3389
Why this is correct
RDP listens on TCP port 3389 by default, so the server-side listener and its local firewall rules must permit inbound connections there. Since the network firewall already allows all outbound traffic, the remaining constraint is confirming the server accepts 3389.
- ✗
Port 23
Why it's wrong here
Port 23 carries Telnet, not RDP, so verifying it tests an unrelated service on the server. It is tempting because 23 is a classic remote-terminal port, and it would be correct for legacy Telnet administration, but RDP operates on TCP 3389, leaving the actual connection failure unexplained.
- ✗
Port 5900
Why it's wrong here
Port 5900 carries VNC, not RDP, so verifying it on the server leaves the actual RDP listener unchecked. It is tempting because 5900 is a well-known remote-access port, and it would be correct when troubleshooting a VNC connection, but RDP listens on TCP 3389, which is the port to verify here.
Go deeper
Related to this question
Learn chapter
Troubleshoot: Network Connectivity
Key term
Remote Desktop Protocol
Remote Desktop Protocol is a technology that lets you connect to and control another computer from a different location, as if you were sitting in front of it.
Key term
TCP
TCP (Transmission Control Protocol) is a core internet protocol that ensures data is sent reliably and in order between devices over a network.
About these practice questions
One of 871 original 220-1201 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 220-1201 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 220-1201 exam.