We recently set up a server on Debian Wheezy Beta 3 (x86_64) which has a native IPv6 connection.

We configured the eth0 interface to get the IPv6 configuration through some post-up hook commands in /etc/network/interfaces. The result is, that after the booting the system up, there is only IPv4 and an auto-configured link-local IPv6 address configured on the interface, as if the command has never been executed.

When we additionally place the commands after the call to ifup -a inside the /etc/init.d/networking init script, everything works as expected and we have a fully configured interface after booting up.

This is quite an ugly way to configure the interface. What are we doing wrong with the ifup post-up hooks? Or is this a bug?

The section from /etc/network/interfaces looks like this (IP-addresses changed):

allow-hotplug eth0
iface eth0 inet static
        address 1.2.3.1
        netmask 255.255.255.192
        network 1.2.3.0
        broadcast 1.2.3.63
        gateway 1.2.3.62
        dns-nameservers 8.8.8.8
        dns-search mydomain.tld
        post-up ip -6 addr add 2001:db8:100:3022::2 dev eth0
        post-up ip -6 route add fe80::1 dev eth0
        post-up ip -6 route add default via fe80::1 dev eth0

I also tried it in this alternative way:

auto eth0
iface eth0 inet static
        address 1.2.3.1
        netmask 255.255.255.192
        network 1.2.3.0
        broadcast 1.2.3.63
        gateway 1.2.3.62
        dns-nameservers 8.8.8.8
        dns-search mydomain.tld

iface eth0 inet6 static
        address 2001:db8:100:3022::2
        netmask 64
        gateway fe80::1

What we added to /etc/init.d/networking:

…
case "$1" in
start)
        process_options
        check_ifstate

        if [ "$CONFIGURE_INTERFACES" = no ]
        then
            log_action_msg "Not configuring network interfaces, see /etc/default/networking"
            exit 0
        fi
        set -f
        exclusions=$(process_exclusions)
        log_action_begin_msg "Configuring network interfaces"
        if ifup -a $exclusions $verbose && ifup_hotplug $exclusions $verbose

        # Our additions
        ip -6 addr add 2001:db8:100:3022::2 dev eth0
        ip -6 route add fe80::1 dev eth0
        ip -6 route add default via fe80::1 dev eth0

        then
            log_action_end_msg $?
        else
            log_action_end_msg $?
        fi
        ;;
…