Chromecast can’t connect to WiFi

Zyxel_JoyLee

When your Chromecast can’t connect, or your phone can’t detect it, the cause is usually Client/AP Isolation, Multicast/mDNS, or band settings on your Zyxel router, access point (AP), or switch. You can start troubleshooting with the checks below.

Suggested troubleshooting steps

1. Turn off Intra-BSS Traffic Blocking or AP Isolation

This is the most common reason a phone and a Chromecast can’t communicate with each other.

• Zyxel router / AP (locally managed): Log in to the web interface and check the wireless settings (Wireless > SSID Setup). Make sure AP Isolation or Intra-BSS Traffic Blocking is Disabled.
• Zyxel Nebula cloud management: Go to Site-wide > Configure > Access points > SSID advanced settings. Make sure Intra-BSS Traffic Blocking and Layer 2 Isolation are both turned off.

2. Check Multicast (mDNS) and IGMP settings

Chromecast uses the mDNS protocol to be discovered on the local network.

• Make sure IGMP Snooping is enabled on your router and switches.
• If your network is more complex, make sure the Chromecast and the phone you’re casting from are on the same VLAN and subnet, so multicast packets aren’t blocked by a firewall or by crossing network segments.

3. Disable MULTICAST TO UNICAST CONVERSION

https://community.zyxel.com/en/discussion/33631/how-to-disable-multicast-to-unicast-conversion