UDP packet loss

Pavel Urban urbanp at mlp.cz
Fri Jun 9 05:29:05 UTC 2006

Danny Mayer wrote:
> Pavel Urban wrote:
>> Patrick Klos wrote:
>>  > In article <e69ccs$cbm$1 at sf1.isc.org>, Pavel Urban  <urbanp at mlp.cz> 
>> wrote:
>>  >> Hello,
>>  >>
>>  >> 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.
>>  >>
>>  >> Udp:
>>  >>     948795842 packets received
>>  >>     149802 packets to unknown port received.
>>  >>     214635022 packet receive errors
>>  >>     1003702082 packets sent
>>  >>
>>  >> I've tried to increase system udp receive buffer 10x and then 100x 
>> with no noticable effect. Do I have to change something in Bind, too? Or 
>> am I  completely wrong?
>>  >
>>  > I'd say your biggest problem is the 214 million packet receive errors!
>>  > Find the source of those errors, and you'll likely take care of your
>>  > problem.  Your machine is tossing 1 out of every 4 or 5 packets!
>>  >
>> I've tried to 'watch' these errors and they seem to be bind-related - 
>> after the service is restarted, these errors stop to occur for some 
>> time. I thought that the cause is small udp receive buffer, but I'm not 
>> a network specialist - do you think it is/may be caused by something else?
>> Thanks!
> Which O/S and which version of BIND?
> Danny

Sorry, this post went initially to bind-users at isc.org; by replying to 
it, it ended up in 'comp-protocols-dns-bind at isc.org'. I've probably 
messed up threads a bit.

As I've stated in my original post, it is

RedHat Linux ES release 4, 2.6.9-34.ELsmp kernel, dual Opteron system
with 6GB ram, no local zones, just resolver/cache. bind-9.3.2-2_EL4


Pavel Urban (pavel.urban at imaginet.cz)
IOL system disaster
Internet OnLine, owned by Cesky Telecom, a.s. (www.ct.cz)
    Vegetables should not operate electronic equipment.
           Computer Stupidities, http://rinkworks.com/stupid/

More information about the bind-users mailing list