UDP packet loss

[bert hubert]

On Thu, Jun 08, 2006 at 04:01:18PM +0200, Pavel Urban wrote:
> I've tried to find out the cause of some strange resolving problem we 
> are experiencing. From time to time, our server seems to ignore some 
> requests, while others are answered promptly. It seems to me that the 
> problem is UDP packet loss.

The symptom is UDP packet loss, the problem is that the nameserver is not
processing UDP packets quickly enough. You can raise buffers but this merely
hides the underlying problem, and also causes new ones as the nameserver
will be answering old & stale questions.

I suggest you look at your system load to see if your nameserver is keeping
up.

A good way to see this is by running vmstat 1 and checking if there is any
'id' capacity left.

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