NetBoot and Multiple DHCP Servers

Hey everyone,
We have a NetBoot machine running here at my school (where I work). It was working like a champ until a couple of weeks ago when our network got upgraded and there are now 2 DHCP servers on our network. That, for some reason, is totally screwing up our NetBooting process.
Here's what I think is happening, and maybe someone can tell me if I right or wrong. NetBoot (or BSDP protocol) is a "broadcast" protocol. (That means it's always just floating around out there on the network. ) NetBoot (BSDP) protocol gets injected into the DHCP stream, and any machine that gets DHCP can get BSDP, and essentially NetBoot.
The problem is with BSDP. BSDP protocol wants to have all of it's "broadcasts" come from the same server. So when we had 1 DHCP server, everything was fine, because client machines would get their whole NetBoot process from one machine... all of the BSDP broadcasts were coming from our 1 DHCP server.
Now, we have 2 DHCP servers. What happens is, a client will get some of it's BSDP broadcasts from one DHCP server, and some from another... which it does not like at all.
I recently read somewhere that it is possible to somehow make one of our DHCP servers the "authoritative" server, to which all of the clients will go to get their NetBooting info.
Does this sound in any way right? Are we on the right track ? Has anyone seen this before? Any help would be greatly appreciated. Thanks a million.
Mike

Now, we have 2 DHCP servers. What happens is, a
a client will get some of it's BSDP broadcasts from
one DHCP server, and some from another... which it
does not like at all.
Not unless your new DHCP server is also a NetBoot server and is set to provide NetBoot services. BSDP and DHCP are not the same thing. If what you were saying were true, it wouldn't be possible to have DHCP and NetBoot offered by different servers.
It IS possible, however, that the two DHCP servers are causing problems by both servicing DHCP requests for the same clients. If you've got multiple DHCP servers on the same subnet (or your router's configured to pass DHCP requests between subnets), you should make sure that only one of the DHCP servers answers requests from any given client. In our world, our Novell server is the default DHCP server on our subnet, but I keep a list of excluded MAC addresses on that server so that my Macintosh clients don't get addresses from it. On the Mac OS X server, I'm careful to limit my address ranges only to those machines which have static address maps in NetInfo. That way, our servers coexist, but they don't overlap.
It's not clear from your message whether your previously solitary DHCP server was your Mac OS X server, or whether one of the two DHCP servers is that box. But whatever the servers are, it might be helpful to turn off one of them to see if the same problem occurs (assuming you can, without major network disruptions). If that's not possible, can you talk to your network admins to see if there's some way to isolate your clients and one of the servers--in other words, see if there's some way to keep DHCP servers from responding to the same requests.
There may be any number of other reasons why this problem has cropped up. You may need to dust off a hub and a copy of Ethereal or EtherPeek to sniff what's happening on the network. You might also try NetBooting in verbose mode, to see where the process craps out. IIRC, there'a decent guide for this kind of troubleshooting over at Bombich's site (www.bombich.com).
Good luck.
David Walton

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