[Pkg-haproxy-maintainers] Bug#726323: Bug#726323: Bug#726323: Bug#726323: haproxy doesn't start on boot due to missing IPv6 address on interface

[Apollon Oikonomopoulos]

Hi Philipp,

On 16:41 Tue 15 Oct     , Philipp Kolmann wrote:
> The IPv6 addresses which are balanced with keepalived are all
> configured with transparent. There I don't have any issues.
> 
> I have the issue with the fixed IPv6 Address of the interface,
> specified in /etc/network/interfaces
> 
> iface eth0 inet6 static
>         address 2001:629:1005:30::11
>         netmask 64

As Vincent pointed out, you're probably hit by IPv6 Duplicate Address 
Detection (DAD). Unfortunately it also seems that Optimistic DAD does 
not work at this stage. This has nothing to do with HAProxy, it's the 
Linux kernel delaying to make the address available to userspace. If 
this is a 100% controllable environment, you can turn DAD off on the 
specified interface, with:

  pre-up echo 0 > /proc/sys/net/ipv6/conf/$IFACE/accept_dad

It's dirty, but it should get you up and running without delays. I'm not 
suggesting you should do it, just make sure you understand the 
implications of this.

In my view, the proper solution would be for ifupdown to wait for the 
address to become available (i.e. leave the tentative state). The only 
thing we can do is warn about this in README.Debian I guess.

Regards,
Apollon