Comment 31 for bug 1003842

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Simon Kelley (simon-thekelleys) wrote : Re: [Bug 1003842] Re: Precise NM with "dns=dnsmasq" breaks systems with non-equivalent upstream nameservers

On 31/05/12 08:47, Thomas Hood wrote:
> In addition to devising an algorithm for dnsmasq to detect all and only
> NNNs, the implementation of which will no doubt take a while, we should
> consider implementing a quick fix too, along the lines suggested by
> Sergio in #19. NM could be changed to do the following.
>
> "If the nameserver address list to be fed to dnsmasq contains one or
> more local addresses followed by one or more non-local addresses then
> run dnsmasq with the --strict-order option."
>
> I must confess that I am not sure what exactly should fall under "local
> addresses" here. In IPv4 I presume that these would be the familiar
> ranges 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16, but what about IPv6?

I think you're right for IPv4. For IPv6, I'm tempted to treat it as a
tabula rasa and explicitly not support NNNs. the rationale being that
NNN support is to work around historical bad practice and such bad
practice is not supported in the brave new world of IPv6. If that won't
fly, then the IPv6 equivalent would be link-local (fe80::/64),
site-local (fec0::/10) and ULAs (block fc00::/7), I think.

> Nevertheless, I think we can safely proceed with this fix without being
> sure that we have exactly the right definition of local address since
> dnsmasq works no worse than libc in strict-order mode.
>
> ** Also affects: dnsmasq (Ubuntu)
> Importance: Undecided
> Status: New
>
> ** Also affects: resolvconf (Ubuntu)
> Importance: Undecided
> Status: New
>