I have a network that advertises IPv6 addresses through IPv6 autoconfig. To allow DNS lookups and to have fancy IP addresses, we setup "static" IPv6 addresses through /etc/network/interfaces:

auto eth0
iface eth0 inet dhcp
iface eth0 inet6 static
    address a:b:c:d:e::f 
    netmask 64

Whenever we now connect through IPv6 Linux uses the IPv6 autoconfig address:

 a:b:c:d:21d:60ff:fe4a:479

and not the static IPv6 address:

 a:b:c:d:e::f

A server on the other side only sees the autoconfig address.

Is there a way to force linux (Debian/Ubuntu) to use the static address for outgoing packets? This is especially interesting for reverse DNS and firewall settings.

I don't want to disable the IPv6 autoconfig since I don't have control over the settings the router advertises.