Cannot access asus router admin page but have full wired internet connection?

[Musafir]

Thanks. Is there a way to force free the memory preemptively so that router does remains accessible?
I want to avoid the situation where router becomes completely unresponsive, and I cannot even reset it remotely.

What should I monitor for? What corrective action should I take? If nothing else, I am ok to reboot the router before it becomes unresponsive.