Install over LAN

[Keith Clark]

I have an old P4 server here running two hard drives in a raid setup 
that I'd like to install Ubuntu.

My present setup is DSL modem into an off the shelf commodity router.  I 
have a machine currently running Ubuntu 12.04.  The 'new' machine cannot 
boot from USB (only a USB-FDD option) and I don't have any media for the 
CD-ROM drive (although it is bootable.).  I realize I could just go buy 
a CDR and be done with it, but where would the fun be in that?

Is it possible to install Ubuntu this way?  I have other devices that 
use the router's current DHCP function so I'd like to leave that the way 
it is.