Network Requirements

The Wifi network must be able to provide a constant bandwidth of 5Mbps to each Chromecast.

A level of 5Ghz is recommended because there is more bandwidth available than 2.4Ghz.

Our solution requires a dedicated Wifi SSID/VLAN for the Chromecast. 

Chromecast service uses the Bonjour protocol (aka mDNS) for service discovery. The Bonjour protocol is based on Multicast. The network must allow Multicast traffic in both ways. 

If any device on the network provides the Bonjour gateway service, this feature must be disabled.

If "Client Isolation" is enabled on the Wifi network, the MAC address of the OnlyCast appliance in the guest network must be added to the Client Isolation Whitelist. 

The router in the Guest Wifi network shouldn't do ARP proxy or ARP poisoning.