UDP packet loss

[Rick Jones]

Pavel Urban <urbanp at mlp.cz> wrote:
> Rick Jones wrote:

>> Now, to actually get a larger socket buffer, you may need to tweak
>> the sysctl settings _and_ something in the named config file.
>> Sysctl to raise the limit and named config file to make sure that
>> named doesn't "undo" it by asking for something smaller.


> That's what I thought. I just need to know what to change on Bind
> level.  Operating system keeps this limit OK, but I don't know if
> Bind is actually using it. I don't think that hardware couldn't keep
> up with traffic (processors are at least 20% idle), about 4GB ram

MP means being able to be saturated while still having idle :) 

> free etc, but maybe there is something more to tweak. Suggestions,
> anyone?

Starting at the root of the bind/named source tree do:

find . -exec grep -l SO_RCVBUF {} \;

and work backwards from there.  A variation would be to replace
SO_RCVBUF with setsockopt.

And/or, if you know the routine used to parse the config file you
could look there.

If there is a configuration option to tell named to set socket buffer
sizes, I hope it treats a value of "0" as "accept what the system has
as the default."

rick jones
-- 
The computing industry isn't as much a game of "Follow The Leader" as
it is one of "Ring Around the Rosy" or perhaps "Duck Duck Goose." 
                                                    - Rick Jones
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