Subject: Re: release and A instead of AAAA?

Re: release and A instead of AAAA?

From: Steinar H. Gunderson <sesse_at_google.com>
Date: Wed, 8 Dec 2010 23:51:37 +0100

Den 8. desember 2010 20:10 skrev William Ahern
<william_at_25thandclement.com> følgende:
> Some will route an IPv4-mapped address through the IPv4 network.

This would be correct behavior.

> Others will route it through the IPv6 network regardless.

This would be broken behavior. (Mapped addresses are explicitly not
meant to be sent on the wire.)

> Still others will just
> drop them entirely because of security concerns--on OpenBSD IPv4-mapped
> addresses are rejected immediately inside both bind(2) and connect(2).

This would be “OpenBSD just wants to be difficult”. :-)

> So an interface isn't really being helpful in crafting mapped addresses
> because the application still has to deal with all of the policy regardless.

You can turn it around; c-ares shouldn't be ignoring to do The Right
Thing(TM) just because there are broken operating systems out there.

/* Steinar */

-- 
Software Engineer, Google Switzerland
Received on 2010-12-08