[dns-operations] All dual-stack DNS servers - any problem with it?

Edward Lewis Ed.Lewis at neustar.biz
Wed May 16 13:25:25 UTC 2007

At 2:42 PM +0200 5/16/07, OndÞej Sur˜ wrote:

>I heard something about bind (acting as resolver) not trying IPv4 on
>some conditions?  Could be urban myth, but it's worth checking...

Not an urban myth, something that is true - for 
old versions of BIND that are still out in the 
wilds.  There are some versions of BIND that do 
give up if the AAAA does not answer but there's a 
workable A.  ISC has fixed this bug but they 
can't recall all the servers that are out there 
with the bug.

I recommend having at least one pure-IPv4 name 
server in the set.  At least *as long as there is 
considerable brokenness* in the IPv6 routing 
system.  (Even if the brokenness is not local to 
you, brokenness is local to someone somewhere.)

.US added a pure-IPv6 server to our set, it was 
noted by IANA we were the first to do that in the 
root zone.  We'll see what comes of that.
Edward Lewis                                                +1-571-434-5468

Sarcasm doesn't scale.

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