Troubleshooting: FortiGate Policy Allows HTTP but Users Can't Browse
A FortiGate administrator configures a firewall policy to allow HTTP traffic from internal users to the internet. The policy uses source address 'internal_subnet', destination address 'all', and service 'HTTP'. After applying the policy, users report they cannot access websites. What is the most likely cause?
Quick Answer
The answer is that the firewall policy only allows HTTP (port 80), but users are trying to access HTTPS (port 443). This is the most likely cause because modern websites almost universally redirect HTTP traffic to HTTPS or require a secure connection, meaning the FortiGate drops the HTTPS packets since no policy explicitly permits TCP port 443. On the Fortinet NSE 4 Network Security Professional NSE4 exam, this scenario tests your understanding of how service objects map to specific ports and the default implicit deny behavior—a common trap is assuming "HTTP" covers all web traffic. Remember that when troubleshooting a FortiGate policy that allows HTTP but users can't browse, always check whether the service includes HTTPS, as most sites now enforce encryption. A quick memory tip: "HTTP is for reading, HTTPS is for securing—if your policy only has one, users are done."
⚠ Common exam trap
A common mix-up: candidates assume 'HTTP' covers all web traffic, but FortiGate treats HTTP and HTTPS as distinct services based on port numbers, and the implicit deny will block any unmatched traffic.
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
✓
The policy only allows HTTP (port 80), but users are likely accessing HTTPS (port 443)
The policy explicitly allows HTTP (TCP port 80), but modern web traffic predominantly uses HTTPS (TCP port 443). Since the service object does not include HTTPS, the firewall will drop HTTPS packets by default unless a separate policy or rule permits them. This is the most likely reason users cannot access websites, as most sites redirect HTTP to HTTPS or require HTTPS for secure connections.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The source interface is misconfigured
Why it's wrong here
No indication of interface misconfiguration.
- ✗
The destination address object 'all' is incorrect
Why it's wrong here
'all' is a valid default address object.
- ✗
The policy order is incorrect and a deny policy above is blocking the traffic
Why it's wrong here
The scenario does not mention any deny policies. Order is not the issue.
- ✓
The policy only allows HTTP (port 80), but users are likely accessing HTTPS (port 443)
Why this is correct
A common oversight: the policy only permits port 80, but most websites use HTTPS on port 443.
Visual reference
Go deeper
Related to this question
About these practice questions
One of 282 original NSE4 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 →
Same concept, more angles
1 more way this is tested on NSE4
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A network administrator configures a firewall policy to allow HTTP traffic from the internal network (10.0.0.0/8) to a web server (172.16.1.10). Users on the 10.0.0.0/8 network cannot access the web server, but other internal users can. The administrator checks the policy list and sees the policy is enabled and in the correct position. What is the most likely cause?
medium- A.The policy is placed below a deny-all policy
- B.NAT is not configured on the policy
- ✓ C.The firewall does not have a route to the 10.0.0.0/8 network
- D.The policy is disabled
Why C: The most likely cause is that the firewall does not have a route to the 10.0.0.0/8 network. Even though the policy is enabled and correctly positioned, the firewall must have a return route to the source network (10.0.0.0/8) for the web server's response traffic to reach the users. Without this route, the firewall drops the return packets, causing connectivity failure for those specific users.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This NSE4 practice question is part of Courseiva's free Fortinet 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 NSE4 exam.