The firewall blocks ExamQR Exam, so candidates can't find the server

Candidate computers find the ExamQR Exam server over UDP port 45454 and connect to it over TCP port 5000. When the firewall on the server computer doesn't let ExamQR receive these connections, candidates see no server, or see it but cannot connect.

How you recognise it

• On the server, under System status on the Dashboard: “The firewall is blocking ExamQR — candidates' machines won't find this server” or “The firewall doesn't allow ExamQR yet — candidates' machines won't find this server”, with an Allow through firewall button.
• On candidate computers: “No server found yet”, or after typing the address: “192.168.1.10 is not responding. Check that the IP address is right, that this computer is on the same network as the server, and that the server's firewall allows ExamQR.”

Likely causes

• Someone chose No when the computer asked for administrator permission, or Cancel in the Windows Security Alert window. Windows then keeps a rule that blocks the app, and that rule wins over any rule that allows it.
• The person signed in to the server computer has no administrator rights.
• A third-party antivirus or firewall filters the network in addition to Windows Defender Firewall.
• On a school domain, a group policy ignores firewall rules made on the computer itself.
• On Linux, the password prompt that opens the ports (ufw or firewalld) was cancelled.

Fix it

1. On the server computer, open ExamQR Exam and go to Dashboard.
2. Click Allow through firewall and choose Yes when the computer asks for administrator permission. If you are not an administrator, ask one to type their password at that prompt. ExamQR removes any rule that blocks it and adds one rule that allows it on every network type. You only need to do this once on this computer.
3. Check that the line now reads “Firewall: ExamQR is allowed”.
4. On a candidate computer, wait a few seconds for the server to appear, or click Enter address manually and type the address shown under Server address on the server's dashboard.
5. If the computer has another security program, allow the ExamQR Exam server program in it, or allow incoming TCP port 5000 and UDP port 45454.
6. On a school domain, ask the IT administrator to allow the ExamQR Exam server program, or TCP port 5000 and UDP port 45454, in the domain firewall policy.
7. Linux: click Allow through firewall and enter your password; ExamQR opens TCP 5000 and UDP 45454 with ufw or firewalld. If the ports were closed again later (for example after a firewall reset), delete the file ~/.local/share/ExamQR/data/.firewall-opened, restart ExamQR Exam and allow it again.

If it still doesn't work

Report the problem from this page and include a screenshot of System status on the server, the Windows or Linux version, and the name of any security program installed. If candidates still see nothing, read Candidate computers can't find the exam server.