aliasing ethernet cards in FBSD

[Gary]

Hello all, 

I have just installed my first FBSD system v4.8, to use as production
mail/dns servers.  I am currently building this now.  I come from a Linux
background, and must say, FBSD is very "smooth," fast, and fun to use.

I need some help regarding ethernet aliasing.  I use djbdns for my DNS,
specifically, tinydns and dnscache for all my builds.. Since my LAN has an
internal cache, this goes on another aliased ethernet, as I cannot have
tinydns and dnscache on the same IP address.  

In Linux, to alias an ether card, I would use something like this in my
etc/sysconfig/network dir.

ifcfg-eth0  with a 192.168.0.100
and 
ifcfg-eht0:0 with a 192.168.0.120

How would I do this in FBSD, setting up an aliased ether to an Ip address?

my current rc.conf file currently contains just the address of the
machine, as such.

ifconfig_rl0="inet 192.168.0.100 netmask 255.255.255.0"

Thanks for any input.

-- 
Gary