Troubleshooting
The guides in this section enable administrators to quickly determine the root cause of an issue, to resolve it, and to get the FreeRADIUS server back into production. The guides also provide information that helps administrators easily debug changes to complex policies.
The most important thing to know about these guides is that method is more important than memorization. That is, there is no one piece of information you can remember that will somehow solve all problems. FreeRADIUS has extensive documentation, and there is no need to memorize it.
Instead of memorization things, you should carefully troubleshoot the proble,. Troubleshooting is the step-by-step method that helps you to determine the root cause of a problem. Once the root cause is determined, you should use similar step-by-step methods to fix the problem, and verify that the fix works.
This process can see, slow, but it is much more productive than making a bunch of changes, in the hope that one of the changes will fix the issue. As the saying goes, slow is fast, and fast is slow.
General Rules
Run the server in debugging mode (radiusd -X). Look at the debug
output. Don’t look at the output of radclient. You cannot debug
server policies by looking at a simple binary `Access-Accept or
Access-Reject on the client.
Common Errors
The common errors page covers the most common errors that people see when trying to configure the server. If you see an error which is unclear to you, you should start on that page.
The error messages produced by FreeRADIUS are necessrily short, and cannot contain a full explanation of the issue. The documentation pages are larger, and therefore contain those descriptions. In many cases, the debug output of the server will point you to a specific documentation page!
How to make Changes
If your server starts up successfully, save a copy of the configuration so you always have a "known working" configuration. When the server doesn’t start up, go back and verify the configuration and read the entire debug output.
Follow these recommended steps to troubleshoot your server:
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Make small, discrete changes to the configuration files.
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Start the server in debugging mode by entering the command radiusd -X
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Verify that the results are what you expect
The debug output show the current configuration and relevant information such as:
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Datastores are connected and operating.
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Test packets are accepted by the server.
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The debug output shows that the packets are being processed as you expect.
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The response packets contain the attributes you expect to see.
Common Issues
Some of the more common issues are covered in the FAQ. The section is divided into the following areas: