Informations about home_server_pool with load-balancing or fail-over

Alan DeKok aland at
Sat Jul 25 14:12:04 CEST 2015

On Jul 24, 2015, at 7:56 PM, Geaaru <geaaru at> wrote:
> I see freeradius documentation but I have some doubt about how
> load-balancing/fail-over it works when is enable status-server or not.
> 1) From documentation I see that an home_server_pool with load-balancing
> split requests between all home server. But FWIK or I understand if request
> doesn't receive a response from first home_server is not send to second
> like for fail-over. Is this correct ?


  The proxy fails over when:

a) the home server is marked dead, and then

b) the NAS sends another packet.

  If the NAS doesn't send another packet, the proxy will not be able to fail over *for that packet* to another home server.  The *next packet* will see that the home server is down, and the proxy will choose another home server

> 3) About status-server check... In my configuration I set status_server to
> yes under security section but If I haven't enable site status (on port
> 18121 for example) I can receive however Status-Server request only on port
> 1812 and 1813. Is this correct?


> 4) home_server gone on alive status only if at least one request is been
> received from server else home_server is leave on "unknown" status. Is this
> correct ?

  Yes.  "Unknown" is equivalent to "alive".  The only difference is that it's a bit more information for the administrator.

> 5) Is there a way to set alive status of all home_server automatically at
> bootstrap ?


> I see that with fail-over if I haven't received request from
> startup (status of home_server is unknown) then on a failure of first
> home_server, request is not sent to second home_server (at least on 3.0.8
> version). Instead, if I have both home_server in alive status and I power
> off first home_server, than request is correctly sent to second on failure
> of first.

  It's more complicated than that.  The NAS has to retransmit.

  Use radclient, with "-r 20", so it sends 20 retransmits.  You WILL see the proxy fail over from one home server to another.

> 6) If I haven't active status-server is there a way to handle home_server
> only alive to avoid zombie period if a request go to failure / timeout ?

  I don't know what that means.

  Alan DeKok.

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