Access to the internetor any other networkis governed by the default gateway ... that you need to reconfigure the gateway on, ...

regularly updating your router’s settings and passwords make it difficult for third parties to guess your router’s access point. Most routers automatically assign a default gateway.

Luckily, accessing the router settings does not rely on Internet access, but rather on a direct ... window and press "Enter." Look for "Default Gateway" to locate the IP address.