M.I.T = Multimedia IT dept.

# ifconfig vlan2 create
# ifconfig vlan2 vlan 149 vlandev vic0
# ifconfig vlan2 inet 192.168.149.254 netmask 255.255.255.0

Sample configuration files:

/etc/hostname.vlan2
inet 192.168.149.254 255.255.255.0 NONE vlan 149 vlandev vic0

/etc/hostname.vic0
inet 192.168.214.100 255.255.255.0

REFERENCE:
http://www.sakana.fr/blog/2008/04/14/vlan-openbsd-a-simple-configuration/