FreeBSD VLAN

I was sitting here at work setting up some VLAN lab scenarios for my CCNA and one of the labs I set up was using 4 interfaces on a FreeBSD box with each interface as a VLAN. After I got everything working on the box, Cisco switch and cisco router I got to thinking what are some practical uses for setting up VLANs on a FreeBSD box?

Pls Enter command on freebsd
" #vconfig add eth[Number Ethernet] [vlan ID] "
Exp = # vconfig add eth0 28
and Ip set on this Vlan Id
" $ifconfig eth[Number Ethernet].[vlan ID] "
Exp = $ ifconfig eth0.28 192.168.0.124/24
Or
Exp = $ ifconfig eth0.28 192.168.0.124 netmask 255.255.255.0 broadcast 192.168.0.255

and see
ifconfig