[dns-operations] best way to reprime root-hints?

Mark Andrews Mark_Andrews at isc.org
Tue Feb 5 05:02:01 UTC 2008

> > This assumes the name servers running on all instances are the same.   
> > Are they?
> i think so, yes.
> > (Note that I assume that all instances on all servers support EDNS0).
> i think they do.
> > P.S. I think setting the limit arbitrarily to 1200 is likely a  
> > mistake.  Someday, not only will we have 13 AAAAs and 13 As, but we  
> > may also have DNSSEC cruft.  Not sure all of that will fit in 1200...
> it was on the hopeful assumption that by that time the maximum minimum
> MTU will be more than 1500, that the recommended default buffer size
> for EDNS0 is 4096.  rare fragmentation/reassembly is better than common
> place TCP.

	Just a reminder for everyone 512 was choosen because it was
	the minimum network re-assembly buffer size.  It was *not*
	choosen to avoid fragmentation.

	EDNS is designed to advertise a bigger re-assembly buffer size
	than the network minimum.

	EDNS sizes are not normally choosen to avoid fragmentation,
	fragmentation is to be expected.

Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: Mark_Andrews at isc.org

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