I have not found a way to make this work but maybe somebody has.. I hope

Prmary DHCP server is Windows 2K DC. Using Siemens VOIP system which
requires option tag 43 to be set. Option tag 60 is set pointing to PXE
Imaging server which is ZEN 7.0.1 running on NetWare 6.0 SP5 in a 3 node
cluster. Configured to bind to virtual IP only.

When on the server LAN everything works just fine. On any VLAN we can not
PXE boot.