Comcast cable internet via ethernet drops sporadically

Just in case I cannot finish this with you and you find you need to start over with someone, you should describe the problem to him or her as, "Sporadically, while using the Internet, my browser becomes unable to open new web pages. Previously established connections, such as Email, continue to work. Rebooting the computer temporarily helps. Changing the cable modem did not fix the problem. Switching browsers did not fix the problem."

I don't want to prematurely focus on your router, but you should also understand that your cell phone company and your school PC do not use it. Even though your router has not changed, if you have had it for several years it is possible that the strains of today's internet use over previous use might be a reason to begin to see failures. On your next reply, can you tell me its model?

The following is not a solution, it's just troubleshooting. Hopefully the results of the troubleshooting will lead us to the solution.

1. Please tell me the manufacturer and model number of your router. For example, "D-Link DI-624 H/W Rev. C2." This can often be found on an FCC-required label on your router. With this, I can look up the features of your router that might affect this problem.

2. Please tell me your Operating System and Version. For example, "Windows Vista Home Premium OEM." Telling me this will help me give you the right commands to use.

3. Let's check to see if your computer is using your router's DNS Relay feature, and let's try to bypass it if it is.

3a. Checking to see if your router performs DNS for the LAN...

These instructions are for Windows Vista. Windows XP commands are similar.

- Open a Command Prompt window: Click on Start, Programs, Accessories, and right-click on the Command Prompt option. Click on "Run as Administrator" (or, if using XP, click on "Open").

- Type the command IPCONFIG /ALL and view the output. Use the scroll-bars if necessary. Locate the section appropriate to your computer's network card. On my computer, this section has the title "Local Area Connection."

- Locate the lines in that section that talk about "Default Gateway" and "DNS Servers." If these lines contain different IP addresses, then ***STOP*** and close the Command Prompt window and do not continue with any more of these steps as your router is not performing DNS functions. If these lines both contain the same IP address, then your router is performing DNS functions for your LAN. This is a feature that can be one of the first to fail when home routers are under stress. Before replacing the router, however, we should test the theory by bypassing the feature.

3b. Setting new DNS addresses

- In the Command Prompt window (from step 3a), type the following command. Please note that the name inside the quotes is the name of the network card from the above step:

netsh interface ip set dnsserver "Local Area Connection" static 4.2.2.1

Note: static with the above command means that your computer will no longer try to automatically configure DNS for you, but will use the 4.2.2.1 for DNS, instead. The reversal of this command is below.

You may close the Command Prompt window. The changes you made will be remembered. A reboot is not necessary.

If you find that you _never_ have the problem after issuing the above command, then you might take this as a sign that your older router may have outlived its usefulness. You can locate the configuration option for your router to turn off DNS Relay, and then reconfigure your computer back to normal (see below). However, if the above command only "seems to help a little" or does not help at all, then a "DNS Relay" failure is not indicated.

(note -- use the command ...
netsh interface ip set dnsserver "Local Area Connection" dhcp
... to reverse the effects of the above command and restore previous behavior. After setting DHCP using the above command, rebooting will cause your computer to obtain the network configuration automatically.)

Please let me know about steps 1, 2, and 3 above.

Thanks

PS: 4.2.2.1 is a reliable public DNS service useful for troubleshooting. Comcast's DNS service is normally reliable, too, but I don't know which Comcast servers handle your area. I chose 4.2.2.1 since it is known to work from anywhere.

Mark, thanks for the comprehensive follow-up here is some of the info you asked for and a little bit of questioning to better understand the problem before changing my DNS settings:

OS: Windows XP Pro not OEM, school enterprise license
router:Netgear WGR614 v4
router firmware: V5.0_02 (V5.0_07 is now availble but there is no mention of bug fixes for DNS problems http://kbserver.netgear.com/release_n... )

Running ipconfig shows that my router is the default gateway and DNS server ie. Default gateway = DNS server = router address = 192.168.0.1
In other words, this means it is acting like a relay, right?

I logged into my router and there is no option for turning off DNS relay. I searched the netgear support site for "dns relay" and "relay" but didn't get any useful hits... they are using some other terminology perhaps? The only DNS setting available on my router is manually setting a primary and secondary DNS server within the router configuration... but then it would still acting like a relay, right?

Altogether, from what I can gather, the router's dns relays are failing because of the hardware is aging? Or is it that I'm entering too many page requests simultaneously such that I exceed the capacity of the router (I've got a sense that I lose my internet connection when I open several tabs in my browser at once)?

In the end I did hardcode in the servers of OpenDNS. While Robb command didn't work I did it graphically by opening my "network connections" then right clicking on "local area connection" and choosing "properties" then selecting "Internet protocol" and choosing properties and from there input the DNS server addresses. There are good direction located at: https://www.opendns.com/start?device=...

I had this problem for several months. It turned out that comcast was loosing a lot of my packets (upwards of 10% at times). Since it was intermittent, comcast didn't want to believe me. I simply made customer support sit on the phone with me keeping a ping going until they saw it too. Then they'd send a technician out who would check the signal strength and replace the splitter. After the 5th technician in a month, comcast finally started looking at the equipment farther away from my house. I think I had to just get lucky and have the problem show up while the technician was there.

I ended up having to deal with several complete outages over the course of a week or so (while they fixed stuff?). Once over the outages the packet loss seemed to go away.

The reason my email stuff worked but not the browsing stuff was that the email packets were smaller and more fault tolerant. It just seemed like my email client was moving very slowly because it had to deal with so much lost information.

Browsing web pages, though, wasn't working because too many packets were being lost and the browser wasn't able to recover from it. It ended up just looking like webpages were down.

If you open a command prompt (start -> run: cmd) and type in "ping -t www.google.com" you can kind of test for packet loss. To stop it hold ctrl and press C. A "good" connection should only drop at most about 1 in 100 packets. So if you start to see stuff like "Request timed out" mixed in with responses, it usually means that information is being lost.

sounds like I have the same issue as you SpicyLemon. I have never been treated so badly by a company when I call comcasts tech support line. They keep telling me its my hardware or router. I have replaced every wire in my house and direct connected the modem. All I get are Comcast reps saying that my signal strenght looks find and that my account is just a recreational account. I can not sit at home waiting for a tech to come every 5 days. I can not play online PC games, stream video, play the Wii online, or even have a nice browsing experience. Of course i have a recreational account. I just wish comcast was not the only provider in town.

Update.
So I have tried the call to comcast support again. I end up getting frustrated on the phone because they only go back to the same ol' line of is it your router or cable or etc.... could be your cable and oh you replaced your cable then it might be the connections on the cable. They will not believe that there is a problem and now I am about to do the last and final step by renting a new modem from them. If this does not fix the issue of the dropped packets they said I would have to call in to have a basic tech come onsite again and do the same tests that the other one did and then they might once again find something wrong with my cables. As comcast states we don't drop packets. Our outside lines are big and sturdy so it must be your house causing your issue that we can't see. It is sad to say but I will be forced to drop my cable internet for the first time since I started back in 1998 with the @home service. My only other option in this area is a sad 1.5 dsl from Qwest.