Welcome to the Rogers Community Forums! 🙂
Thank you for posting your query in the Community; it's okay to post in an old thread since your inquiry is relevant.
We have discussed connecting an external router to the hub in previous posts. You can follow the solution post of this thread to log into MF275R.
I have found the following walkthrough to log into your DIR-835 Router. And please check out the post by @Breeze99 to connect your D-Link router to the hub.
Let us know if you have further questions.