We have ~300 WIZ108SR running on a network using DHCP. We are using some combination of HW 1-1 with FW v2.20 and HW 1-2 uses FW v4.04. Our settings are:
Baud Rate 115200
Debug Messages disabled
Data bits 1
Stop bits 0
The issue we are having is the wiznet devices are discovered by the DHCP server, offered an IP address reservation but fail to request from the DHCP server and so never receive an acknowledgement. We end up with all of these devices making these requests continuously. We are concerned it is disrupting other critical parts of our network. We have other instruments and computers running DHCP on this network and they do not have this issue so we strongly believe it is related to the wiznet implementation of DHCP.