LinuxQuestions.org - crazy problems with DHCP server and 10baseT hub

Hello,
I've been scratching my head for several days, and I've finally decided to ask in the forums, to see if anyone has any ideas.

My current network layout is as follows:

[internet]
|
||--------[mail/webserver]
||
[router/switch]-----[computer 2]
||
||--[main computer]
|
|
[cluster-master node]
|
[switch]----[node 1]
||
||--------[node 2]
|
---------[node 3]

(I apologize for my poor ascii diagram).
My main computer, webserver, and another computer connect via a router to the internet. These are fine though, and have no problem.

I've also started to build a cluster (although it's not really doing anything special :p ), running debian sarge (stable), with 2.4.27 kernel(s), isc's DHCP server, and with the above configuration works just fine.

The problem arises when I try to add a different router/hub (I'm not sure which. I think it's a hub)(Dec repeater 90TS). What will usually happen, is that no lights on the hub will light, indicating that nothing is detected, and no DHCP address is given to the nodes. It didn't appear to be the network cards (all identical "tulip" cards), as the one connecting to the home network was given a DHCP address from the router to it just fine, but They were replaced anyway (with intel 10/100 cards), and the light on the hub for the master node now lights up. :? The work nodes light still remains off, and no DHCP address is given.

The REAL craziness, is that when I add the old switch (a billion bipac 5102 configured to be used as switch only, btw) back in like so:

[master node]----[hub]----[switch]-----[work nodes]

...lights for both master node, and work nodes(switch) both come one, and the whole thing works perfectly. ?:/

I need this hub to work, because I have a lot more nodes to add, and the switch only has 4 ports, so If anyone has any ideas of whats going on here I would appreciate it. :)

additional info:
- The DHCP server on the master node is also running with a tftp server (atftpd) for network booting.
- The old hub is supposedly managed via smnp, but I can't for the life of me, figure out how to "manage" it.
- The cluster it's self was build using DCC (debian cluster components, although I'm not using any of the clustering features yet (Haven't advanced far enough in programming yet.)

EDIT: New information!

Although the pxe dhcp client, system imager dhcp client, and worknode dhcp client don't seem to work with the new setup, I run DSL on one of the computers, and although it didn't get an IP (some security feature or something), The light on the hub did come one momentarily, and it did talk to the DHCP server.

Does this mean it's likely a configuration of the dhcp client, or mabye the driver for the network card?

Any speculation appreciated. ;)