Well, I finally found my problem. I am running ZeroShell in a VM on an ESXi 6.7.0 server, and using USB Ethernet controllers. ESXi 6.7.0 server does not support USB Ethernet controllers, however there was recently a “USB Network Native Driver for ESXi” released as a Technical Preview. The only problem with the USB Network Driver technical preview is it only does 1000Mbs/Full duplex. The fixed wireless router is at least four years old and appears to only support 100 Mbs/Full duplex. Once I put a little five port switch between the ESXi 6.7.0 server and the fixed wireless router, ZeroShell was able to get a DHCP address.