Cannot log into router/admin

I have always been able to log into my router and did so before my vacation. Now that I am back I cannot log in anymore. I would go onto the rougerlogin page and enter the user and password but it just continues to ask me the user and password. I have not changed it at all and I have tried to factory reset it. I have tried the original admin/password they give you in the beginnging and nothing is happening. It doesn't even tell me it's the wrong password, it just has me logging in contantly. Was wondering if the site was down by any chance? Or how can I resolve this.

My router/modem is actually a C7000 model but for some reason would not let me post this model.