IPTables and DNS

[Jason Dixon]

On Jan 16, 2005, at 8:39 PM, Ed Greshko wrote:

> Rudolf Ladyzhenskii wrote:
>> DNS is UDP port 53, not TCP
>
> Actually, it is both....if you are going to be doing zone transfers 
> that is.

Actually, it can also use TCP if it's unable to trim the response to 
fit in a 512 octet UDP datagram.  This can happen with large responses, 
i.e., Akamai or Yahoo hosts that have multiple entries per A record.  
This is also necessary to support A6 and DNSSEC.

</trivia>

--
Jason Dixon
DixonGroup Consulting
http://www.dixongroup.net