Use a non-default login password for both routers. Don't allow remote (internet) login unless you need to use that feature.
Protect both wireless networks with WPA2-PSK or WPA-PSK encryption with a strong passphrase. If you are not going to use the ARRIS's Wi-Fi disable it.
Allow physical access to the routers only to people you trust.
Protect both wireless networks with WPA2-PSK or WPA-PSK encryption with a strong passphrase. If you are not going to use the ARRIS's Wi-Fi disable it.
Allow physical access to the routers only to people you trust.