Set up internal network domains for my servers

[legit]

I have a development server behind my pfsense box that I would like to give a domain so that I don't have to type out it's ip.  I was wondering if anyone could tell me if I can use the dns package to do that and how I would set that up?

also, I want these domains to only be visible behind my pfsense box, is any special setup required for this?

[wallabybob]

Enable DNS forwarder on pfSense and at bottom of web page Services -> DNS Forwarder add entry for server.
Configure local systems to use pfSense as DNS. (This should happen automatically if local systems are using DHCP to get IP address and DNS.)

If the server has a private IP address it won't be accessible from outside your local network unless you have done something to pfSense or your modem to make it visible (e.g. port forwarding).