Below are some tips from Google: https://productforums.google.com/forum/?hl=en#!topic/chromecast/pzpgXAtuDZ0
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Hi everyone!
We often hear that users have issues with their router settings when they first set up Chromecast. Here’s what you need to Set Up Chromecast (or a Mondo+ connection to your smartphone):
- Enable: Universal Plug and Play (UPnP), multicast, Internet Group Management Protocol (IGMP)
- Disable: AP/client isolation, virtual private networks (VPNs), proxy servers, IGMP Proxy
- Please note, each router and its settings are a bit different. Contact your router manufacturer for details.
Still having trouble with setup? Next steps:
- Please keep in mind that resetting or making changes to your router settings may have unintended consequences. If you have questions or concerns, please consult your router manufacturer or ISP before making any changes.
- Check out the Chromecast Troubleshooter.