Proxy issue - Failing proxied request for user error

James Wood james.wood at
Tue Jul 16 23:53:56 CEST 2019

Hi Alister

I initially thought it was the sql module as we write accounting updates to
SQL, but I disabled that for a while and still the same. So, moving
forward, I decided to rule out the master server and just test by sending
traffic direct to the public IP of the home server directly.

I ran a tcpdump against a customer IP sending us accounting packets. When
reviewing in Wireshark I can see a (small) percentage of packets that do
not show any Accounting-Response reply, and then a few seconds later the
NAS re-sends and then we reply as expected. So something on the home server
itself is not right, it seems to 'miss' incoming packets.

I ran the server in debug mode at the same time as the capture and the
first packet did not even show up at all, as if the server never received
it. But, the packet was received by the server as per the wireshark capture

Any thoughts on this?



> The target server or the network is broken between the proxy and the home server.

> You'll have to go through a process of elimination:
> Eg...
> Run home server RADIUS in debug and look to see if its telling you about problems ...
> Check for lost packets by comparing sent to received (you might have done this already)
> Check for processing time at the home server (from a packet capture you can trivially get the latency graphed which is the first thing)
> If you see spikes in latency corresponding to the errors then ....
> Depending upon what the accounting is doing you might have database issues or filesystem/disks getting overloaded.
> If the traffic is very bursty you might find you need a larger amount of memory on the home servers socket queues.(This is often a balancing act between loss and latency).
> Is the home server doing something else that uses up disk/cpu/memory resources periodically

> Basically its network and server diagnostics and tuning 101s. Find what is slow / dropping the requests fix that and only that and check again.

> Alister

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