I've setup an OS X 10.6.5 machine with all of the user accounts and software that I'd like on all of the clients. I used the SIU on our 10.6.5 OS X Server to create a NetRestore image from that machine. I have configured the NetBoot service on the server to use that image.
I have followed the steps in the book Beginning Mac OS X Snow Leopard Server to get to this point.
When I try to boot the client from the network, I see the connection in the NetBoot service logs:
Dec 1 10:16:12 myserver bootpd33093: server starting
Dec 1 10:16:12 myserver bootpd33093: server name myserver.example.net
Dec 1 10:16:12 myserver bootpd33093: interface en0: ip 172.16.2.218 mask 255.255.255.0
Dec 1 10:16:12 myserver bootpd33093: interface en1: ip 172.16.2.217 mask 255.255.255.0
Dec 1 10:16:12 myserver bootpd33093: bsdpd: re-reading configuration
Dec 1 10:16:12 myserver bootpd33093: bsdpd: shadow file size will be set to 48 megabytes
Dec 1 10:16:12 myserver bootpd33093: bsdpd: age time 00:15:00
Dec 1 10:16:12 myserver bootpd33093: service time 0.000020 seconds
Dec 1 10:16:27 myserver bootpd33093: BSDP DISCOVER en0 1,d4:9a:20:c5:5d:be NetBoot001 arch=i386 sysid=iMac10,1
Dec 1 10:16:27 myserver bootpd33093: replyfile /private/tftpboot/NetBoot/NetBootSP0/Pairing Station NetRestor.nbi/i386/booter
Dec 1 10:16:27 myserver bootpd33093: replying to 0.0.0.0
Dec 1 10:16:27 myserver bootpd33093: BSDP OFFER sent 1,d4:9a:20:c5:5d:be pktsize 370
Dec 1 10:16:27 myserver bootpd33093: service time 0.001017 seconds
Dec 1 10:16:27 myserver bootpd33093: service time 0.000012 seconds
Dec 1 10:16:27 myserver bootpd33093: service time 0.000025 seconds
Dec 1 10:16:27 myserver bootpd33093: service time 0.000012 seconds
Dec 1 10:16:29 myserver bootpd33093: service time 0.000032 seconds
Dec 1 10:16:29 myserver bootpd33093: service time 0.000011 seconds
Dec 1 10:16:40 myserver bootpd33093: service time 0.000026 seconds
Dec 1 10:16:40 myserver bootpd33093: service time 0.000012 seconds
At this point the ServerAdmin interface shows that the client is connected (see image below), but that it's stuck in the NetInstall stage and at 0%. This continues for a couple of hours and then the client connection drops.
There's a pretty good netboot troubleshooting guide here: http://www.afp548.com/netboot/mactips/netboot.html and Apple's own one http://support.apple.com/kb/TA21155
The most common causes are a problem with the image you're trying to deploy or a problem with the network between the server and the client. Your issue implies the former as it looks like it bombs out while negotiating basic network details with the client, but I'll try and cover all areas.
So.. what does the network between the server and the client look like? If you cross subnets then you'll need to create IP helper entries for the netboot server (and DHCP server if separate) on the switches/routers handling the routing between the client and server subnets.
Do you get the same result if you plug the client and the server (and DHCP server if separate) into the same "dumb" switch? I'd pay a lot of attention to this aspect of the process as your log suggests that it's during the address negotiation stage of things where you have a problem)
Is the image file actually available on the network? If it's shared via AFP for this process then can you connect to it normally via afp from another client? Can you substitute a "known good" basic image for your desired image, to eliminate a problem there?
Lastly, as an aside rather than a troubleshooting step, have you considered using deploystudio? It's a lot less hassle to manage than the basic netboot process.