4xx errors. Troubleshooting 4xx errors 

4xx errors could be caused by malfunction on the Origin side or incorrect CDN-resource's settings.

Check the content availability on the Origin-source

Check your CDN-resource's settings 


Check the content availability on the Origin-source

Request the content from the origin-source and ensure that you get a HTTP 200 response code.

If you use IP Whitelist on the origin or use DDoS protection serviceensure that CDN-edges IPs are whitelistedUse the API-request above to get the list of Public IP

curl -i -X GET https://api.gcorelabs.com/cdn/public-ip-list

Since we constantly update the Public IP list, we recommend you to run script for the regular whitelist updating. You can also use HTTP Request Header for the authentication on your origin. You may find out more about the Origin ACL here. 


Check your CDN-resource's settings 

  • Ensure that the CDN- resource is activeIf you have created a new resourcewait until its configuration applied on CDN-edgesUsually, it takes 15 minutes. 
  • Ensure that the Origin is able to respond to the requests from CDN-edges by chosen Origin Pull ProtocolYou may learn more about this option from the article. 
  • Check the Change Host Header option. Make sure that the option is active and the value is the same as the Origin Source or match with the host that you have set up on the Origin. You may find more information about Host Header here. 

Go the Reports tab to track the amount of 4xx errors.

To receive more details about user’s requests to resources use the Raw logs optionIt is a paid featureThe Raw log receiving setup flow and the description of logs’ fields are located hereIf you want to activate this featurecontact your account manager or send a request to technical support (support@gcorelabs.com).

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