Howto further debug when freeradius does not respond or log anything?

Alan DeKok aland at
Wed Mar 4 19:06:34 CET 2015

On Mar 4, 2015, at 11:27 AM, Gary Holtkamp <dosenfleisch at> wrote:
> Next step was to restart freeradius manually on the console with the "-X" option to see what might be going on.
> But freeradius didn't log anything. Next try was with "-X -x", but also no output there.

  Then the NAS isn’t sending packets.

> I then made sure with wireshark/tcpdump that the Cisco is really sending out radius packets and that they reach the freeradius server. They do and the packets look good in wireshark, nothing that is apparently broken with them. But freeradius is not sending out anything.

  So… run the server in debugging mode to see what it’s doing and why.

> When I restart the Cisco, the problem goes away, so I'm quite sure that it's the Cisco that is sending broken
> packets somehow.

  It’s more likely that the packets aren’t reaching FreeRADIUS.

> Does anybody have an idea how to debug this further? I could ask Cisco, but they'll probably blame it on freeradius :-)

  It sounds like a networking or maybe a firewall problem.  For some reason the packets aren’t reaching FreeRADIUS.

  If “radiusd -X” prints nothing, then FreeRADIUS is working fine.  The problem is that it’s not getting packets.  And that’s not a problem you can solve by poking FreeRADIUS.

  Alan DeKok.

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