Noob quetsion Why there is a dns ( 192 168 * * ) with my google dns that my router is using? And the most important point, Is it safe to use?
If someone attacked my network would my dns ( 192 168 * * ) be a privacy concern?
Addresses within the 192.168.0.0/16 (192.168.0.0 to 192.168.255.255) range are private (as in, they cannot be routed to the internet). This means that this address is probably your router. It’s most likely doing your local name resolution. It fallbacks to Google DNS if it cannot resolve the address it’s looking for. It’s a fairly normal configuration.
Using Google DNS is not very private and you could use something such as Unbound to resolve and cache DNS locally.
Also if someone enters your network, you’ll probably have other concerns to worry about, like finding the source of the breach (like an exposed service on the internet). I guess they could poison your DNS cache but I’m not sure if it’s a widespread kind of attack for home networks.