Bind 9 truncating responses

[Brad Knowles]

At 9:28 AM +0000 2005-04-22, <stephen.vickers at n3k.co.uk> wrote:

>  First things first: I understand that 50 NS records in a zone are not
>  good practice however situations require that this be the case.

	No, it's not good practice.  In fact, it's one of the worst that 
I've ever encountered, and I was the guy who committed the Heinous 
Crime Against the Internet by figuring out how AOL could stuff 49 IP 
addresses for MX servers into the DNS.

>  Are the NS and A records considered required/important for the response
>  to an A record query?

	No, they'd be "additional" information for that query.  I'm much 
more concerned about what happens when someone does an "NS" query for 
your domain and the 50 names and IP addresses can't fit into a single 
512 byte packet, so you're not truncating in the "additional" 
section, but instead in "authority".

	Get these things called Layer 4 Load-Balancing Switches.  Use 
them.  Don't advertise 50 NS records.

-- 
Brad Knowles, <brad at stop.mail-abuse.org>

"Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety."

     -- Benjamin Franklin (1706-1790), reply of the Pennsylvania
     Assembly to the Governor, November 11, 1755

   SAGE member since 1995.  See <http://www.sage.org/> for more info.