Intermittent Comcast Internet connectivity

I can't believe it's been 8 days on this one and there hasn't been a response from Comcast. I was trying to give them a chance first but..... well... yeah.

First we need to troubleshoot our router. Next time this problem pops up, before restarting anything, try to ping your router, modem and other computers on your network. You could also try to open a shared folder from each computer and the control pages for the router and modem. We're just trying to see if things are still communicating.

To run ping test, fist look up the IP addresses of the devices to test. To do this on windows, hold the windows key and press the R key. Type cmd into the run dialog that pops up and press enter. You should see a black screen appear that says something along the lines of "Microsoft Windows XP..." This is the "Command Prompt." At the command prompt type "ipconfig" and press enter.

Something similar to the following should appear in the command prompt,

Windows IP Configuration

Ethernet adapter local Area Connection:

Connection-specific DNS Suffix:
IP Address: 192.168.1.100
Subnet Mask: 255.255.255.0
Default Gateway: 192.168.1.1

Record the "IP Address" so we can use it on one of the other computers in your home.

To do the actual ping test, open a command prompt and type "ping <ip>" but change "<ip>" to one of your recorded IP addresses.

To test connectivity to the router, try opening the router configuration. The most common way of doing this is opening a web browser and typing the router's IP address into the address bar. Most of the time the IP will be either 192.168.1.1 or 192.168.0.1. You may have to look this up in your router's manual.

To test the modem, try to pull up it's diagnostics page. I don't know if this is universal, but where I had Comcast, just north of Atlanta, this was done by typing the IP 192.168.100.1 into the address bar of an internet browser. This also works for me here with my Bresnan Cable. In both cases I had a Motorola Surfboard modem. It's black, stands on end and has the Motorola logo above the lights. If you get some sort of Page Load Error, you'll have to contact Comcast and find out how to access the diagnostic page of your modem. Judging by experience you'll probably have to keep at it a bit before they'll tell you. Don't let them tell you that it's not possible because it is. Tell them you don't mind holding while they find out how to do it.

Here's how to interpret a ping result.
A successful ping has four lines that look similar to this

Reply from <ip>: bytes=32 time=1ms TTL=64

This is followed by a summary looking something like this

Ping statistics form <ip>:
Packets: Sent =4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 3ms, Average = 0ms

The interesting part of the results are the 4 lines and the "Lost =" part of the summary. If the four lines are anything but "Reply from ..." then there's the ping was unsuccessful.

If pings are unsuccessful to other computers in your home as well as the router then there might be a problem with your router.

If pings are successful to your modem, router and all your computers, your router is fine.

Second, let's check out the modem. This is a little trickier and will require help from comcast customer support. One of the catches with this is that ISPs have a nasty habit of blaming modems. They love to blame modems because they're difficult to troubleshoot and they're often not the property of the ISP. Even when the modem is being rented by the ISP, they like to say it's the modem so that they can appear to be doing something.

Here are some things you can do to test your own modem. First, make sure you can access the diagnostics page. Second, call comcast and verify the mac address of your modem. There's a problem with their system where sometimes it just "forgets" mac addresses. Be very pressing and have the double check that it's in the system and that it's set permanently

If the problem persists and you are renting your modem call them and make them come out and replace it. If you own you modem, tell them that you want to make sure it's your modem before spending the $50 to replace it. Don't let them bully you into buying a new modem.

Every time you have to reset your modem, call Comcast and make them run some diagnostics. Schedule a technician to come out and check everything in and around the house. Explain the problem but again, don't let them bully you into thinking it's your modem. Like I said earlier, they like to use modems as a scapegoat. Ask them what exactly happens that causes it to require a reset. It's difficult to tell whether your modem stopped talking to the comcast routers or the comcast routers stopped passing information to/from your modem. It's been my experience that 99.99% of the time it's the latter.

If you own your modem and comcast has made an actual effort to fix the problem and they still insist that the problem is your modem, don't buy a new one. Rent one from them for a month to see if the problem still exists. DO NOT let them take your modem. They have a nasty habit of saying that the modem is theirs even if it isn't.

If your problem happens even once, call them up and get huffy. Let them know that the problem has happened now with two modems, so it isn't the modem that's the problem. Schedule a tech to come out, check everything/pick up their modem and switch back to your modem. Also get them to refund you for the modem rental as you only got it because of their insistence that it's the modem that's the problem.

If you change the modem and you don't have to reset it for a month or two, then you've got a couple options. Either a) keep renting the modem or b) buy a new one and stop renting it.

As you can see I'm pretty skeptical of comcast and their troubleshooting abilities. Keep at it. Bug the crap out of them if you have to. Make lots of techs come out if you need to. For tech visits, make them find a time that works for you. Your time is more important than comcast's. You are paying them for their time. They are not paying you for yours (or refunding you for the time you've wasted on them). If they've been there a couple times and have noted that everything is okay inside the hosue, you can have them come out and check everything outside the house even if you're not there. Make them leave the slip in the door so you know they were there.

I guess that's all I've got. Good luck.</ip></ip></ip></ip>