Unless EnableMediaRouter is set to Disabled, setting MediaRouterCastAllowAllIPs to Enabled connects Google Cast to Cast devices on all IP addresses, not just RFC1918/RFC4193 private addresses.
Setting the policy to Disabled connects Google Cast to Cast devices only on RFC1918/RFC4193.
Leaving the policy unset connects Google Cast to Cast devices only on RFC1918/RFC4193, unless the CastAllowAllIPs feature is turned on.
| Registry Hive | HKEY_CURRENT_USER |
| Registry Path | Software\Policies\Google\ChromeOS |
| Value Name | MediaRouterCastAllowAllIPs |
| Value Type | REG_DWORD |
| Enabled Value | 1 |
| Disabled Value | 0 |