Mike O'Connor wrote:
auto eth0 iface eth0 inet static address x.x.x.242 netmask 255.255.255.192 gateway x.x.x.254
iface eth0 inet6 static address x:4200:401:10::3 netmask 64 gateway x:4200:401:10::1
This style also works; personally I find it prettier; IPv6 equivalent should be straightforward. (I'm sick of ifupdown's hokey old noweb codebase.) allow-auto lo dmz iface lo inet loopback # Until I think of a better place, add blackhole routes when the # loopback interface comes up. These ensure (unused) private IP # ranges aren't accidentally sent to the internet. Note that even # without this, Internode filters outbound packets to private IPs. up ip route add blackhole 10/8 up ip route add blackhole 172.16/12 up ip route add blackhole 192.168/16 up ip route add blackhole 169.254/16 up ip route add blackhole 203.7.155/24 down ip route flush type blackhole iface dmz inet manual up ip link set dev $IFACE up up ip address add dev $IFACE brd + 203.7.155.1/26 #up ip address add dev $IFACE brd + 203.7.155.2/26 # was satay #up ip address add dev $IFACE brd + 203.7.155.9/26 # was teriyaki up ip address add dev $IFACE brd + 203.7.155.19/26 # was soy up ip address add dev $IFACE brd + 203.7.155.20/26 # was office nat down ip address flush dev $IFACE down ip link set dev $IFACE down