Proxy listens to TCP home server on UDP port

Nikolai Kondrashov Nikolai.Kondrashov at
Fri Aug 1 17:16:50 CEST 2014

Hi everyone,

Red Hat QA has noticed that a FreeRADIUS v3.0.1 server set up to use TCP with a
home server still listens for replies on UDP. I couldn't find any requirements
for that in RFCs and I lack the necessary protocol knowledge to conclude if
this is a correct behavior. Could someone say if this is right or not?

Could this have been done to simplify handling of mixed-protocol server pools?

Some more details follow.

The default configuration was modified to use TCP everywhere. I.e. to
have default server listen for authentication and accounting on TCP, to have
inner-tunnel virtual server listen on TCP, and to have localhost home server
protocol specified as TCP. See attached patch for exact changes done.

After starting "radiusd -X" these are the last few lines printed:

     Listening on auth proto tcp address * port 1812 as server default
     Listening on acct proto tcp address * port 1813 as server default
     Listening on auth proto tcp address port 18120 as server inner-tunnel
     Opening new proxy address * port 1814
     Listening on proxy address * port 1814

And "lsof" outputs these lines for radiusd:

     radiusd   2728  radiusd    3u  IPv4  21180      0t0  TCP *:1812 (LISTEN)
     radiusd   2728  radiusd    4u  IPv4  21181      0t0  TCP *:1813 (LISTEN)
     radiusd   2728  radiusd    5u  IPv4  21182      0t0  TCP (LISTEN)
     radiusd   2728  radiusd    6u  IPv4  21183      0t0  UDP *:1814

The original bug reported by QA:

Thank you.

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