BIND and TCP

[Peter Dambier]

Barry Margolin wrote:
> In article <dh3gif$1fm7$1 at sf1.isc.org>,
>  Peter Dambier <peter at peter-dambier.de> wrote:
> 
> 
>>It happens from time to time that DNS via UDP does not work. Bind 
>>automatically
>>switches to UDP then.
> 
> 
> Are you sure about that?  I think it only switches when the UDP response 
> has the Truncated flag set, as recommended by the RFCs, not when UDP 
> just fails.
> 

You are right, Barry, the Truncated flag was set. That is why it switched.

Sometimes it is the AAAA records, sometimes DNSSEC? and sometimes the
text records for anti spam filters that make a packet bigger than 512.

Sometimes I dont see why the Truncated flag comes up in the first place,
but come up it does.

-- 
Peter and Karin Dambier
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