Resolve captive portal issue on Chrome OS
If you're running Chrome OS version 62, and you're seeing the error Device cannot connect to any wireless network or Network not available, you may need to allow access to additional hosts through your firewall. The hosts listed below must be accessible via HTTP port 80 in order for Chrome OS 62 to detect the device as connected to the Internet. If your firewall supports wildcards, you may be able to use a wildcard to whitelist alt*.gstatic.com.
In addition to allowing these hosts through your firewall, if you perform TLS or SSL inspection on your network, you’ll need to also follow the instructions on how to Set up a hostname whitelist.
Hosts to whitelist
To resolve the captive portal issue with Chrome OS 62, try whitelisting "alt*.gstatic.com". If your firewall doesn't support wildcards, whitelist the following list of hosts.
Article last updated on December 22, 2017