On Tue, Oct 20, 2015 at 06:26:38PM +0200, Baptiste wrote:
> > Also, we will have to address the issue that a server may just use
> > a single address-family, therefor we have to fallback between A
> > and AAAA, because a NX on a AAAA query doesn't mean there are no
> > A records.
>
> Hi Lukas,
>
> I do agree on this point.
> A simple option in the resolvers section to instruct HAPoxy to not
> forgive on NX and failover to next family:
> option on-nx-try-next-family
I personally find this confusing from the user's point of view. My
translation of what it does is to allow cross-family requests instead
of limiting requests to the preferred family.
Thus it seems to me that users will have to carefully configure both
this option and the prefer field to select the required family. In
practice I guess most people will simply want "v4only" or "v6only"
as alternatives to "prefer-ipv4" or "prefer-ipv6".
When you know that you can only use IPv4 to join the next server, I
think this :
server remote1 remote1.mydomain check v4only
is more obvious than this :
option on-nx-try-next-family
server remote1 remote1.mydomain check prefer-ipv4
Also, it covers the case where some servers are known to support both
protocols while others are limited. This allows for example to join
the same remote server over two possible families behind a DSL line
which uses a random IP address after each reconnection :
server home-v4 home-v4.mydomain check v4only
server home-v6 home-v6.mydomain check v6only
And since we already have v4only/v6only on bind lines, the analogy
seems easy to remember.
Willy
