How Nginx behaves with "proxy_bind" and DNS resolver with non matching ip versions between bind ip and resolved ip?

[shmulik]

Hello,
I'm working with the proxy module, and with a dns resolver configured. The
traffic i'm using is both ipv4 and ipv6.

I'm trying to understand Nginx behavior when using "proxy_bind" directive
and when the resolver returns both ipv4 and ipv6 addresses.

In particular i'd like to understand what happens when:

1. "proxy_bind" binds to an ipv6 address, and the resolver returns only ipv4
addresses (and the other way around - binding to ipv4, resolving only to
ipv6).

2. "proxy_bind" binds to an ipv6 address, the resolver returns both ipv4 and
ipv6 addresses, but the first attempted ip address is an ipv4 address (and
the other way around - binding to ipv4, first attempted is ipv6).

Can you please shed some light on this?

Thanks,
Shmulik Bibi

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,255814,255814#msg-255814