Ugh...I'm out on a 'help save my sanity' campaign ;-)

I know it's possible to netboot an iMac - how exactly are y'all doing it?
I think I'm missing something crucial, *somewhere*.

I can get the iMac to do the bootp part just fine - with tcpdump on the
FreeBSD box that is serving as a bootp and tftp server, I see the req/response
ok and I know from running bootpd in debug mode, it's giving out exactly
what I want to see... sets ARP address of imac to what its MAC address is,
no problem there.

Am I supposed to boot directly by specifying the Ethernet device at
the OF prompt? So far I'm using:

0 > dev /multiboot open

because that's the only way I know about.

The 'Network disk' pops up right after the bootp request is answered. Click
on it, then click on 'start' (or whatever it was), it sends a single packet
full of 0's (null src and dst ethernet MAC address, null bytes in packet, etc).

Don't see any TFTP requests.

Info: Rev B iMac, OF 3.0.b2. I can supply further information per request -
ie the OF device tree, current OF settings, tcpdump log (isn't long..about a
page, couple packets).

Basically, I have default-client-ip, default-server-ip, and default-gateway-ip
set in the OF vars on the iMac to appropriate values. I don't think any other
variables were touched except auto-boot? was set to false.

So...what am I majorly missing? Any suggestions/hints/tips/pointers would be
*much* appreciated :-)

-Dan