Cross Subnet Netboot Issues

Question

Hello,
I've been working to set up a netboot and Open Directory server in school district. We have the network segmented into VLANs by campus with different subnets for each. The changes have been made to the router to allow bootp/bsdp (IPHelper address set and relay agent on) to communicate across subnets, but I am still unable to netboot/netinstall across subnets.
Watching the logs on the server when I attempt to, it seems to be communicating partially as seen here:
Jul 19 12:48:37 axposeidon bootpd[1822]: BSDP DISCOVER [en1] 1,0:16:cb:8e:50:a6 NetBoot035 arch=i386 sysid=MacBookPro1,1
Jul 19 12:48:37 axposeidon bootpd[1822]: BSDP OFFER sent [1,0:16:cb:8e:50:a6] pktsize 369
Jul 19 12:48:37 axposeidon bootpd[1822]: BSDP DISCOVER [en1] 1,0:16:cb:8e:50:a6 NetBoot035 arch=i386 sysid=MacBookPro1,1
Jul 19 12:48:37 axposeidon bootpd[1822]: BSDP OFFER sent [1,0:16:cb:8e:50:a6] pktsize 369
Unfortunately it fails to actually boot the machine. Im not positive what's going on but it seems like its sending a response back to the netbooting machine but the machine is not getting it and its resending?
The OS X Server is an Intel Xserve running 10.4.10 (though we've been experiencing this issue since as far back as I've been trying with 10.4.8), the image was created in 10.4.8, and works on the local subnet (including multicast ASR). The booting machine is, as noted above, a Macbook Pro.
As a side note, when booted into the OS, the machines can see the server in the Startup Disk preference pane.
Any suggestions or ideas? Let me know if there's more information I can give that will help.

Answer 1

In our district there are multiple public and private subnets. The public and private combination I have the server on currently just happen to be on this physical network, so they are sharing the same router.
I think Im getting a little lost on what you're asking so I'll explain our network structure a little further. The district runs a VLANed network with a different public and private subnet for each campus (the private subnets function mostly as IP address overflow when the public subnet IP limit is exceeded). The network is predominantly PC based and implements active directory servers. The Xserve simply operates as a standalone server currently just handling some web serving tasks and a netboot server.
The issue, regardless of the public and private subnet interfaces on the server, is that I am unable to get anything to boot from another subnet than the one the xserve is running on. If I run it on the public interface, local machines boot perfectly, but I a log like the one above if I try and boot from another campus (ie another VLAN or subnet). To test it locally I've been running it on the private subnet interface (on the same physical network segment) to boot machines on the local public subnet (which fails with the above log).
According to Apple and other sources, all that should need to be configured is our CISCO routers need to be set to pass BOOTP information across VLANs/Subnets, which we have configured (using the IP helper-address and DHCP relay agent), but as stated, the connection is still not succeeding.
I'm checking with our network engineer on a few specifics on how the routers are configured to make sure they are set properly for the forwarding, but he's not available at the moment.
I applogize if this doesnt address the information you're needing, but please let me know if it does not, and I will try my best to get you the needed information.