Here's what I have in my hostname.tun0 to support openvpn. In openBSD, I found the tun won't come up WITHOUT an IP address. Somewhere in the chicken-and-an-egg dance that openVPN-BSD do, I found this the best way to satisfy both.
Code:
root@gw:/etc/ovpn # pg /etc/hostname.tun0
inet 169.254.235.1 255.255.255.252 169.254.235.2
!/sbin/route add 169.254.235.0/24 169.254.235.1
I'm sure other openvpn.conf and hostname.tun0 combinations work as well.
/S