can we disable AAAA queries in the resolver ?

Luigi Rizzo rizzo at icir.org
Sat Aug 2 03:08:56 PDT 2003


On Sat, Aug 02, 2003 at 09:59:18AM +0100, David Malone wrote:
> On Fri, Aug 01, 2003 at 11:52:00PM -0700, Luigi Rizzo wrote:
> > My understanding is that there are multiple buggy components here:
> > my ISP's nameserver certainly shouldn't behave so badly on AAAA
> > requests, and the applications should not bother asking AAAA queries
> > when the kernel has no ipv6 support.
...
> (Strictly speaking, you shouldn't cripple the resolver to not look
> up IPv6 addresses if none are configured 'cos you might want to
> look up the IPv6 address for some other reason than making a
> connection.  There is a AI_ADDRCONFIG flag for getaddrinfo that

i know, but what is happening is that all these applications
(including sendmail and our ssh, for what matters)
are broken in that they look for an AAAA record just for making
a connection. And then it is easier to have a sensible
default (that can be overridden by those apps who really need it)
than one which is correct but depends on too many things
[over which one has no control] to behave correctly.

> tells it to only look up addresses if you have an address in that
> family configured.  For some reason it isn't mentioned in our man
> page. I'm not sure what the status of our implementation is either...)

browsing through the source code there is a bunch of
'options' in resolv.conf that are not mentioned in the manpage.:

timeout: T
attempts: N
debug
no-tld-query
inet6
rotate
no-check-names
edns0
a6
dname
nibble: suffix
nibble2: suffix
bitstring: suffix
v6revmode: single|both


	cheers
	luigi

> 	David.
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