C6300 unable to change dns settings.

[Belcantor]

I am no longer able to specify which dns servers I wish to use. When I attempt to change them to for instance the google dns servers (8.8.8.8 or 8.8.4.4), when I click apply the modem responds with invalid ip and returns to the former page where the dns servers assigned by my isp remain. Any answers on how to solve this? I was able to do this when i first acquired the cable modem but am no longer able to do so.

[TheEther]

It's possible that your ISP installed firmware that locked out changes to the DNS servers. If this is, in fact, true then you really only have two choices.

1. Override the DNS settings in all of your devices. Obviously, this is a pain.
2. Dump the C6300 and get a separate modem and router.