Troubleshooting Mindset Series #023: When a User Can Browse Some Websites but Others Keep Failing

1. Scenario / Issue DescriptionA user reports that internet access is working, but certain websites cannot be opened. Other websites load normally, and the problem may affect only specific users or categories of websites.
The first assumption is often that the internet connection is unstable or the website itself is down. However, when an SWG is involved, several factors may affect the result, including access policies, URL categories, authentication, DNS resolution, and HTTPS inspection.
The key question is: Is the website unreachable, or is the request being blocked somewhere along the way?
2. Troubleshooting ApproachStep 1: Identify the Scope

• Is the issue affecting one user, several users, or an entire network segment?
  
• Does it affect one website or multiple websites?
  
• Can another user access the same website from the same network?
  
  
  

Start by identifying the pattern before changing any configuration.
Step 2: Check the Actual Failure

• Record the affected website URL and the exact error message.
  
• Check whether the failure occurs immediately or after a timeout.
  
• Test whether the issue is consistent or intermittent.
  
• Check DNS resolution and basic connectivity where appropriate.
  
  
  

Different failure symptoms can point to different causes.
Step 3: Review SWG Logs and Policy Matching

• Check the access logs at the time of failure.
  
• Identify whether the request was allowed, denied, or affected by an authentication issue.
  
• Review the matched access policy and URL category.
  
• Check whether the user's group or policy assignment is correct.
  
  
  

Do not assume the expected policy is the one actually handling the request.
Step 4: Investigate HTTPS and Authentication
If the logs do not immediately explain the failure, check whether authentication requirements, certificate validation, or HTTPS inspection could be involved.
Compare the affected website with a working website and look for differences in the observed logs and error messages. Avoid disabling security controls simply to make the website work.
Step 5: Make a Targeted Change and Verify
Once the evidence points to a specific cause, make the smallest appropriate configuration change.
Retest the affected website, confirm that other websites still work, and verify that the intended security policy remains effective.
3. Common MistakeAdding a broad allow rule or bypassing the SWG without confirming the root cause.
This may restore access temporarily, but it can also weaken security controls and leave the original issue unresolved.
4. Troubleshooting MindsetWhen some websites work and others fail, do not treat the problem as a general internet outage.
Instead, follow this sequence:
SCOPE → REPRODUCE → CHECK LOGS → IDENTIFY THE CAUSE → VERIFY THE FIX
The goal is not merely to make the website accessible. It is to understand why the request failed and correct the issue without introducing unnecessary exceptions.
5. Key TakeawayA working internet connection does not guarantee that every web request will succeed.
In Athena SWG troubleshooting, the failure pattern, access logs, and actual policy match provide a stronger starting point than assumptions.
6. Community DiscussionFor those who have worked with SWG deployments, what do you usually check first when a user can access most websites but a particular website keeps failing: the access logs, URL filtering policy, authentication, or HTTPS-related settings?
Share your approach or a troubleshooting lesson from your own environment. Different experiences can help us narrow down these cases more effectively.
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Thanks to share!