comcast modem issue

bookishspider

Ok so my sister was having issues with her internet so i thought i would work on my troubleshooting skills and go over to her house and try to figure it out since I am trying to get into IT and have taken several computer and networking courses. So I went over there and her computer is reading the modem has a good signal but no internet access. I tried to ping the modem from a laptop and it went through successful. I tried resetting the modem and unplugging the modem still no luck. After that I decided to call comcast and they said they could not get a signal from the modem. They said they will send a technitian next week but i am still curios on what could be the issue here? It is an older home and has some questionable wiring. She also has in issues with getting some channels and can not access on-demand and I dont know if it could be related or not. This made me question on whether IT is for me since I could not resolve the issue any input would be appreciated....thanks guys...

MTciscoguy

At this point, if you don't work for Comcast, then you won't be able to troubleshoot it, I would suspect that the problem is outside the house in their cable feed. Could be any number of things that is causing signal loss, I just trouble shot one the other day for the local cable company that was over a mile away from the house that was having the problem.

seigex

When troubleshooting, you always want to eliminate whatever part of the path you can until it starts working, and then move backwords from that until you find the problem.

When it comes to cable modems, you have control over everything from where the TAP hits your house from the street, to all the in-house wiring. In my charter system, I can unscrew the cable right where it comes from the pole into the distribution block on my porch. I would plug the modem in there, power on the modem, plug the laptop directly into the modem and allow DHCP to assign an IP and test from there.

If that doesn't work, then it's a cable company issue. They can tell you over the phone if there are other outages in the area, since all neighborhood users share the same street level distribution block. If they don't notice any, then it's likely some kind of attenuation or coax malfunction between the TAP and the entry point into the house and there's not much you can do until they come out.

bookishspider

Since they are able to get some cable channels but no internet at all do you think that would still be a comcast issue?