[CentOS] BIND issues, server not responding

On Thu, 23 Aug 2007, Feizhou wrote:

>
>>  You only need the tcp rule if you plan on serving up zone
>>  transfers, not if plan on only requesting them.
>> 
>
> Well, very rare but answers that are over 512 bytes will have to be 
> sent over tcp since the rfc 1035 mandates maximum 512 bytes for the 
> udp payload. So tcp is not just for zone transfers only.

Note that by default Win 2003 uses a packet size of 1280 per Paul 
Vixie's suggestion in RFC 2671 section 4.5.1. I don't know if any 
other OS implementations do the same.

In any event, I've found it helpful to allow up to 1280 bytes of DNS 
UDP traffic. Setting the limit at 512 triggers a noticable number of 
retries, at least in our environment.

-- 
Paul Heinlein <> heinlein at madboa.com <> http://www.madboa.com/