Debian: how to set up VLAN interface
apt-get install vlan
modprobe 8021q
grep -q 8021q /etc/modules || echo 8021q >> /etc/modules
vim /etc/network/interfaces
auto eth0.99 iface eth0.99 inet static address 192.168.99.1 netmask 255.255.255.0 vlan-raw-device eth0
ifup eth0.99