Internode, NBN and OpenBSD

I (used to) run an OpenBSD router on a PC Engines APU2 for my home network connectivity. Internode provides their HFC uplink on VLAN tagged 2. The APU2 has 3 RJ45 ports, em{0,1,2} with em0 being my uplink, configured in /etc/hostname.em0:

up

My home network is a dual-stack IPv4/6 with a prefix delegation provided by Internode. The existing PPPoE configuration in /etc/hostname.pppoe0 looked like this:

inet 0.0.0.0 255.255.255.255 0.0.0.1 \
        pppoedev authproto pap \
        authname 'xxxx@internode.on.net' \
        authkey 'xxxx' \
        up
inet6 eui64
inet6 autoconf -autoconfprivacy
!/sbin/route add default -ifp pppoe0 0.0.0.1
!/sbin/route add -inet6 default -ifp pppoe0 fe80::%pppoe0 -priority 8

To communicate over the VLAN we need to create another /etc/hostname.vlan2 file with the following contents:

vnetid 2 parent em0 txprio 1
up

This uses the same ethernet port as before but with the vnetid set to 2 for VLAN tagging. txprio 1 also needed to be added to ensure the wrapping worked.

We can now update the PPPoE configuration use the VLAN:

inet 0.0.0.0 255.255.255.255 0.0.0.1 \
        llprio 1 mtu 1440 \
        pppoedev vlan2 authproto pap \
        authname 'xxxx@internode.on.net' \
        authkey 'xxxx' \
        up
inet6 eui64
inet6 autoconf -autoconfprivacy
!/sbin/route add default -ifp pppoe0 0.0.0.1
!/sbin/route add -inet6 default -ifp pppoe0 fe80::%pppoe0 -priority 8

There was a bit of trial and error getting the final settings but the llprio 1 parameter was required for anything to work and the mtu 1440 was needed after some SSH sessions failed to start.