[outages] 4.2.2.x DNS?

[Tim Wilde]

Patrick W. Gilmore wrote:
> Works here.
> 
> However, we are downstream of Level 3 / as3356.  I heard a rumor they
> ACL'ed queries from sources outside their downstream cone.

Based on some (relatively unscientific) experimentation, this does
appear to be true.  From sources that reach 4.2.2.1 via what appear to
be peering links (such as an XO / Level(3) interconnect) queries time
out, while sources that reach 4.2.2.1 via what appear to be transit
links have no problems with consistent resolution.

I can't really blame them, as a) open recursive DNS servers are rife for
DNS amplification abuse, and b) this must be an enormous resource
consumer for them.  Probably a boon for OpenDNS and any others in the
open/semi-open resolver space.

Regards,
Tim

-- 
Tim Wilde, Senior Software Engineer, Team Cymru, Inc.
twilde at cymru.com | +1-630-230-5433 | http://www.team-cymru.org/