Why do I always have to unplug/reconnect my cable modem & router?

This has been an ongoing problem for me and I am hoping someone can shed some light on why it happens. Probably about once a month on average my cable internet / wireless router setup stops working. Even my wired connections lose their internet access and rebooting the modem, router, and/or PC don't seem to fix the problem. How I usually end up fixing it is by shutting my PC down, unplugging both the cable modem and router, turning the PC back on and then plugging both devices back in. Once they reconnect, then the connection usually works again.

I always figured this issue was related to my specific cable modem and/or router, but just last night I installed a brand new Motorola SB6121 modem and Zyxel NBG4615 router. Everything worked fine until I got home tonight when my internet access wasn't working. I tried a PC reboot and router reboot and it still didn't work, so I went back to my old unplug the devices trick and my internet access started working again.

Can anyone explain why this happens and whether there is an easier way to fix it or, better yet, a way to prevent it entirely? Do other people have this problem where they have to frequently reconnect their devices?

 

:sigh:

have you called your cable company to complain?

 

I have called before, but their response has always been that the signal is fine on their end, and that does seem to be the case since reconnecting the devices (or removing the router from the picture entirely) always solves the issue... so unfortunately I'm not sure what I can really complain about because I don't know what is causing the connection to go down.

 

Insist that the cable company read the noise level from the equipment on your end. With your 6121 modem they should be able to do that easily.

Failing that, ask for a service tech to come out and clean up the lines. The cable company may or may not respond to that but remind them it's their responsibility to deliver a usable signal inside of the house.

 

If you cant do that at least make them drop the price or offer you some sort of deal.

 

Ask the company to check the upstream SNR for both your modem and the upstream card. Also have them look at the historical data for the upstream card. If everything checks out there, have them check the insertion failures and the power adjustments of the modem. If they check out fine as well, its in issue with your router acquiring the WAN IP Address and I would look into a firmware update on the router. The likelihood its an issue with the DHCP pool of your ISP is very slim, but it wouldnt hurt to ask them to check it.

 

for one week (maybe kinda tough), remove the router from the equation. Only connect one computer directly to the modem and see if it fails

 

Thanks guys. I have Comcast coming out in the morning.

The problem got significantly worse to the point where I could barely even get connected yesterday, even without the router. After rebooting the cable modem probably 20 times it went completely dead and wouldn't even power on anymore. I returned it for another SB6121 today and got everything up and running again with Comcast on the phone, but it did take quite a few power cycles before everything finally connected. The agent agreed to send a technician out to check my lines since I have been having so many problems recently. There is a chance that I just had a bad modem to begin with, but I still think my signal may have also contributed to the issues. From what I can tell though, my numbers all seem to be within spec:

 

You have allot of uncorrectable blocks there, especially when compared to the correctable ones. Uncorrectable blocks equates to packet loss. That is your issue. Your downstream SNR and signal levels look fine, unfortunately that snapshot does not show the Upstream SNR. I would bet that you either have a bad fitting at the tap, a bad ground block that has accumulated water due to a bad weather seal, or a faulty distributional coupler (DC).

 

Well, Comcast came out and checked all the signals and said everything looks fine. The only thing the technician did was replaced a coupler that was a little loose on my coax cable coming out of the wall, but I seriously doubt that had anything to do with the problem. I will have to continue to monitor the situation and maybe escalate my problem if it continues.

But is that significant when compared to the total # of codewords? The % of uncorrectable codewords is a tiny fraction of a percent, somewhere around .0001% of the total.

 

did you ever try plugging ONE computer directly into the cable modem? You probably want to do this for a week or so.

If the cable company stuff and cable modem check out, there is a distinct possibility that the router or the inside cat5/6 wiring is bad.

 

I did and I still had trouble with the old cable modem, but I haven't tried it since I swapped that modem out yesterday. I also haven't been disconnected since yesterday either, so it may be that the modem was the main culprit anyway.