#
#   /etc/network/interfaces
#

# Loopback.
auto lo
iface lo inet loopback

# Another IPv4 loopback.
auto lo:50
iface lo:50 inet static
    address 192.168.0.1
    netmask 255.255.255.255

# Another IPv6 loopback.
iface lo inet6 static
    address 2000:www:xxx::zzzz
    netmask 128

# Physical interface.
auto eth0
iface eth0 inet manual
    mtu 1508
    pre-up /sbin/ifconfig eth0 mtu 1508

# Vlan 100: IPv4 address.
auto eth0.100
iface eth0.100 inet static
    address <IP_ADDR>
    netmask <IP_MASK>
    gateway <GATEWAY>
    dns-nameservers <DNS1> <DNS2>
    mtu 1500

# Vlan 333.
auto eth0.333
iface eth0.333 inet manual
    mtu 1500
    up /sbin/vconfig add eth0.333 400

# Vlan 333.400: IPv4 address.
auto eth0.333.400
iface eth0.333.400 inet static
    address 10.10.10.2
    netmask 255.255.255.0
    mtu 1500
    pre-up /sbin/ifconfig eth0.333 up
    post-up /sbin/ip route add 10.3.0.0/16 via 10.10.10.1 src 192.168.0.1
    post-up /sbin/ip route add 10.4.0.0/16 via 10.10.10.1 src 192.168.0.1
    post-up /sbin/ip route add default via 10.10.10.1 src 192.168.0.1

# Vlan 555: IPv6 address.
auto eth0.555
iface eth0.555 inet6 static
    address 2001:wwww:xxxx::2
    netmask 64
    mtu 1500
    post-up /sbin/ip -6 route add default via 2001:wwww:xxxx::1 src 2000:www:xxx::zzzz

# End.