Where doe PXWWorx get "transaction server"

[wsanders1]

We are trying to reconfigure our network so that ZenWorks boot clients get their initial DHCP information from the local router rather than using DHCP relay..

When I try to boot a client, I can successfully load dinic.sys via TFTP on the "distant" Zen imaging server, apparently based on the initial DHCP parameter "next -server". So the host is getting an IP address, route, and the address of the TFTP server. This setup also works to successfully boot generic Linux with PXElinux.

But with Zenworks, after it loads dinic.sys it doesn't know how to contact the Zen imaging server via UDP port 4011, the next step in the boot process:

DHCP (succeeds)
PreWorx Pty Ltd
Issuing New DHCP Request
Local IP: 10.3.1.100
Subnet Mask: 255.255.255.0
Transaction Server ID: 0.0.0.0
Error! No Response from port map service
Zenworks shutting down.

So - what DHCP parameter / option is used to communicate the "Transaction Server" to the booting client? It's NOT "next-server" or "boot-server" as far as I can tell.

Thanks,

-Wiley Sanders
System Administrator
St Marys College of Calfornia