I suspect that the freeradius will return failed at once when "username" attribute is not found

and because the username attribute won't be included in the "access-accept' packet .

The "sql" can be executed successfully when host B acts as authentication server.

So maybe I should ask can freeradius be configured as both authentication server and proxy server at the same host ?

Hope someone can help on this. Many thanks!

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You should make the SQL query so that it won't make an error when certain
attributes are not present or empty.
See the example sql.conf file.

Turn sql traces on and run in debug mode to see what queries are done.
Check why they are failing and correct the queries.

--
Groeten, Regards, Salutations,

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