We run an Active Directory system which also handles DHCP. I realize the netsus appliance's netboot system uses dhcpd to facilitate the booting process and that it's custom tailored to never give out IP Addresses, only netbooting.
We have IP-Helpers on the vlans we're netbooting from pointing to our DC's for DHCP, as well as the NetSUS appliance. Here's the weirdness. The .nbi only shows as a bootable option on the mac if it has previously received a DHCP lease on the vlan. If it has say, been offline for more than the lease time (ours is 48 hours) and then hardwired in and option-booted to try and image it, it will never "see" the netboot server. After booting the machine normally into OSX and receiving a DHCP address, I can then shutdown the machine and the netboot images are visible during an option-boot.
Historically we've used DeployStudio (and still have it running on a different vlan until we make the 100% switch to casper) and have never encountered this issue. I imagine its localized to the difference between what OSX is doing compared to the custom linux implementation of the netSUS appliance. I've enabled logging on dhcpd and can see the INFORM and ACKs being sent back to the clients. I'm not sure what other logging I can enable to try and debug why the nbi isn't being broadcast.
I haven't checked the tftp logs because it doesn't seem to be getting that far. Anyone have any ideas as to what might be causing this weird behavior? My working theory is if the machine is offline for too long and without a lease, it attempts the netsus appliance first, is told there are no free IPs in the pool (but here's a net-boot location!) and then the client moves on to the next DHCP server on the vlan (and ignoring the netboot I guess?). It obviously can't contact the netboot server without an IP yet.
I noticed in the logging and in dhcpd.conf the argument "allow unknown-clients", which lends support to the theory that this requires an existing DHCP lease. Is it at all possible to get this scenario to be more consistent?
