I have one of the worst ISPs (Comcast) ... but they have a monopoly and I'm stuck with them. Things do work fine most of the time, but far too often my internet will just cut out for no reason. Sometimes rebooting my modem/router helps, sometimes it doesn't (but then everything works a little while later).
I very strongly suspect the problem is my ISP, but if I call them up and say as much, they claim all they can do is send out a technician, and if it's my equipment's fault I'll get billed $100+ for the visit.
My question is, how can I prove to myself (and Comcast) that it isn't my equipment (or if it is my equipment, how can I tell whether it's the modem or router, so I know which to replace)?
EDIT: Someone closed this as unclear, but I can't fathom why! My internet stops working periodically: how do I tell which component (of the three responsible: modem, router, ISP) is the root cause ... what's confusing about that?
31 Answer
Easy test is to jack straight into the modem and then run a continuous ping to an address. Using google's DNS address is usually a good indicator.
Open command prompt and run ping 8.8.8.8 /t and let it run to see how many times you get a "request timed out" alert. Then, after you find failure or success with that, add your router back into the mix and do the same thing.
