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.

Hi Exx0dus!

Have you had any success with this issue? It looks like I'm running into exactly the same problem right now.
I signed up with Comcast Cable a month ago and everything was great until about 4/5 days ago. I was playing online and i got the most incredible lag. I exited and found that my browsing speed was very low, also. I tried again the next day and found I could not connect to the net at all! I called Comcast and sure enough, I was told to swap my modem. But why would my modem break suddenly? Or my router? Most strangely, yesterday, I was able to connect again, albeit with unacceptably slow speeds and many dropped packages.

Here's what I've done so far:
Connected 2 different laptops (both connected fine before) both through the WLAN router as well as directly to the modem. one is XP sp2 and one is vista64home
Powercycled everything in different order
pinged google. (about 25-50% lost packages, reasonable ping of ca. 60 in most cases)
checked my router settings for DNS resolution (it's not defined in the router)

I'm pretty sure it's the line itself that causes the problem. Did you ever have a technician measure the cable?

Thanks! I would love to hear any info on this!
Marc

Marc,
Comcast didn't want to fix the issue and really didn't care at all. It has been resolved not because of Comcast caring but because of a lucky event! Here is my rant and answer.

I renting a modem from comcast as they said it was my own modem causing my issue. This was the last thing in my house they could put the blame on so I did it. It didn't change anything. Shocker! What did change was when I picked my modem up they said I could upgrade to standard cable from basic for 2 bucks more a month for 1 year (promo). This I said would allow me to watch some good college football games. So the guy came out a week later to upgrade me. Here is the kicker. He found that they put a trap on my house and also a trap in the box on the corner on my line. I was double trapped. He took it off and it fixed my internet problem that comcast said I wasn't having for 2 months. It was their line not mine. They were so kind to not charge me for the 3 dollar modem rental lol!. I told them they should give me back my last 2 months of payments. They didn't.

So short and sweet. Comcast audited my neighborhood and didn't look at how THEY set up my cable. They double trapped me and then told me for two months that it was my cable and everything else in my house. The only way it was fixed was me upgrading to a promo so they would look at their lines like I told them too.

Marc, I hope this helps. forgive me for my rant.

Exx0dus, thank you for the update and great that it's working for you now!

It certainly looks like something happened to my line on the weekend. Robb, I appreciate that things just blow out. But in my experience, if electronics go bad they exhibit more consistent fail behaviour. In my modem's case it seems to do everything it can with the signal it gets.
I've dug a little deeper and found out that my signal-to-noise ratio is ca. 28 dbmv. (You can look up your signal as it arrives at the modem in the modem settings). According to various forums and websites this is much too low, as the minimum is 30 and the recommended minimum 33.
When I run ping -n 100 to google, I have a packet loss of about 40%. Sometimes higher. Needless to say, internet usage is impossible.
I've tried using a different cable outlet, but it's even worse there. I'll try swapping my modem next. If this doesn't resolve it, then either Comcast needs to examine the line (and hopefully find something) or I need to cancel Comcast, as I'm working from home most of the time and NEED high speed internet for that. Cancelling the broadband part of a double-play bundle will be a whole new joyful experience I'm sure.

Thanks for you input!

I bet if they dig up the underground wire like they finally did in my case, all your problems would be solved.

Please read my case, it was a happy ending only after some scary behavior on my part at the expense of my local Comca$t management (well worth it IMHO).

/bow Robb!

I got a new modem today at the service center. Signal strength as measured on the modem is perfect now. I had issues getting it registered and spent an hour on the phone with customer support. For some reason i could ping everything, but not open the pages in the browser.
Flushing DNS and powercycling helped in the end. Back at full speed! Yay!

Thanks for all your comments. And I must say, as much as I usually bitch about customer service, all my dealings with comcast reps so far (5 different people) have been good. Very courteous and helpful. Even if sometimes I kinda sensed that when she was quiet for a while she was asking her supervisor for instructions. But that's ok! As long as the customer is helped! Good job, girls!

trying to connect to the internet is like watching paint dry with comcast. started good went down hill from there. cable isn't any better...mjturner@comcast.net...but not for much longer...

Hi. I have the same problem like Exx0dus, for like 3 months now....It's so damn annoying. Here is a short description of my problem. I browse the web then suddenly I get no response from the server. Can't open any page from 3 different browsers. My online radio stops but here's the weird part. My MSN connections stays on and also the lights on the modem and the router say that I have not lost the connection. Vista doesn't say that I lost the LAN connection to the router. After 10-15 seconds Internet comes back by itself and after 30-60 minutes the same story repeats again. I have Linksys WRT54G v2.0 with DD-WRT firmware v24 SP1. The router works flawlessly for as long as I have it. I never had any kind of problems with it. I had set up the DNS servers to OpenDNS servers and evrything was fine. Untill 3 months ago. I tried eveything, static IP's, changing the DNS, direct connection to the modem, you name it. I called Comcast only once and they gave me the same bullshit procedure....turn of the modem, turn of your PC, yada yada yada....the lady that probably doesn't know the difference between IP and ISP just did the "reboting the modem for Idiots" procedure. As I read above that the problem was the trap, I think that might be the issue here....but how am I gonna convince comcast that. I don't want to go through all the standard "beginers" procedures..that will take forever. Please if you know a better way to fix this let me know. My email is jolebole[at]gmail.com.

Thanks a lot.

I've been experiencing something similar. Every 40 minutes, my connection hiccups, causing me to drop from any games I'm playing and killing my internet radio. Unfortunately, the problem is on their end. Here's what's happening:

1. The DHCP server is currently handing out 40 minute leases.
2. When it notices my lease is about to expire, my router starts asking the DHCP server to renew the lease.
3. The DHCP server ignores all renew requests. Eventually, the lease expires.
4. Now that the lease has expired, the DHCP server issues a new lease.

Unfortunately, the few milliseconds between when the lease expires and a new one is issued are enough to disrupt my connection.

Well, it seems I'm running into the same issue with hiccups. For some reason, it is only my computer that seems to be having these issues from the router. An ipod touch, three other computers, and two xbox 360's have had no troubles with connecting to the internet. I'm tried working with no other devices plugged into the router, plugging directly into the modem, etc.At the moment, I'm using 802.11n with a minimum signal strength of 84% and the speed fluctuates from 11Mbps to 54Mbps. I've been forced to use opendns since comcasts dns servers had almost no response a majority of the time.

Ventrilo seems to take nearly ten seconds from server join and clicking on a channel to actually entering it. Ping is a low 30-50 until someone talks, then it skyrockets to an average of 3000

I'm running cFosSpeed to monitor my connections and it seems that my connection keeps dropping repeatedly. Even trying to load google goes to about 15kBp/s then drastically starts dropping until I have no tx/rx going on. I'm lucky to have a send of 31B/s when it gets back.

I've gone to numerous troubleshooting sites, ran suggested spyware/virus scans and aside from the typical tracking cookies, nothing has turned up.

One thing i did notice was that whenever my packets were dropped, svchost.exe immediately started making anywhere from two to ten DNS_c connects to the selected DNS server (both comcast and openDNS)

Ping statistics for 208.69.36.230:
Packets: Sent = 49, Received = 15, Lost = 34 (69% loss)
Approximate round trip times in milli-seconds:
Minimum = 46ms, Maximum = 495ms, Average = 193ms

I have been experiencing these "hiccups" in my internet connection as well, very similar to Chris S's. I have ruled out all of my hardware as the problem: replaced the modem, bypassed the router completely, changed computers, cords, etc, but nevertheless the connection never fails to drop 5-6 packets approx every 50 minutes, which in turn obviously causes intense lag or complete disconnection from my MMORPG or when i'm remoting my work computer from home. I have called Comcast, and a technician came out and pointed some numbers at me said everything is fine with my signal even tho i showed him a multiping chart graph of exactly where the connection was dropping (he prolly had no idea what it meant). It appears as tho something such as a DHCP lease expiration is happening on my gateway every 50 minutes or so that's causing my connection to hiccup. Unfortunately, like everyone else, getting Comcast to acknowledge that this is a problem on THEIR end is a very difficult, extremely stressful and drawn-out process. I'm going to call them once more and demand the problem be fixed within a reasonable time period. If not, then they'll have one less customer and one less recommendation of whom to choose for ISP.

I am new to this posting thread and I have a similar problem to most of the people here. Last Christmas my family got 2 new computers and we set up a network. We do A LOT of online gaming and there was never a problem until about 4 months ago i had a router go bad. Purchased a new one (we do not use wireless) and it worked great up until about 1 1/2 months ago. We started getting disconnected frequently at times from our game. At times it is very bad and we cannot stay connected for more than about 5 minutes at a time. We called comcast and they sent a technician out who could not find anything wrong and suggested that it is our router. Also we were charged $20 for the service call and they didnt even do anything to fix the problem. So I bypassed the router and connected directly to the modem with one computer and had the same problems. So obviously it's not the router. Had an online tech do an online check and at the time he checked the connection and what not everything was fine. So is it possible that this is an issue having to do with lots of people in the area using comcast internet at the same time? It does seem to be worse on weekends and in the early evening. I was always under the impression that the main downside to cable internet ws the drop in speed if there were lots of people in your area using the same service. If this is the case is there a solution? Also it is not related to the game we play ( I dont think) because when this is happening to our game play it also affects web browsing as well. Web browsing slows down signifanctly and at times pages take forever to load up and sometimes dont load at all. So whats going on do you guys think ? I am by no means a networking guy or a tech guy however it just seems like this is an issue with either loads of people at one time or possibly some damage somewhere in our neighborhood?Ideas, suggestions please. I have a tech coming this saturday to upgrade me to digital cable and digital voice, but I am not sure I even want to do this if I will continue to have internet issues.Jowebee

You know I find it very interesting so many people are experiencing similar problems. Before I had a tech come by and 'physically' check my system an online tech checked my modem and signal and whatever else he could and said he saw no problems. Then a tech came by and checked stuff and found no problem. Yet the problem exists. It is so frustrating trying to do anything online much less do some online gaming. It has gotten so bad that at times i cannot even stay connected longer than a few minutes. I just don't get it. Everything worked great for so long and then started going downhill fast, and now its worse than it ever has been. New modem...new line from the box to my house. I wonder what its gonna take to get this corrected. I am almost ready to sacrifice speed for reliability and look at Qwest. Any one else who has posted here have any ideas.

This problem has been happening all night tonight...It is horrible.

I have been using Comcast Cable for more than 2 years, Only in recent like 2 months or so, I experienced the network drops, it is exactly like the folks described here: in Browser, no internet at all. Once reboot (i.e. unplug and replug the power line) the Modem (Moto sb5101), everything is fine again. Sometimes, it happened a few times a day, sometimes, several days no problem. I figure this has to do with Comcast. I have not contacted the support yet because I wonder how useful that would be.

I've been using Comcast Cable Internet for a long time and have never had any problems until we moved into our current home. Our internet drops constantly (at least once or twice a day) and Comcast has blamed it on just about everything they can. They refuse to send a tech here to check everything unless I pay them, which is absurd. The very first thing they blamed it on was the splitter, changed, no difference. They then blamed it on gaming, I know it has nothing to do with that. I've even replaced my router and that hasn't helped. If it weren't for DSL sucking so bad and Comcast having a monopoly around here, I would unsubscribe from their service.

I believe the tech's who set up my cable did something that are causing this problem. I got into an arguement with the techs because our landlord had paid them to come out and setup cable throughout the entire house, he [landlord] told us we would have cable in anyroom in the preinstalled jacks after we contacted comcast to turn on the cable [verified the setup before I called]. We call them, they come out, they wanted me to pay again to have them turn on and "hook-up" cable for the entire house. I told them they were crazy and wanted me to pay them $17/jack to turn it on in the house. I could understand if they had to do anything, but they or other technicians had already hooked it up for the entire house through the landlord.

They disconnected THEIR splitter so the live line would run through my basement, directly into my living room and hooked all the other leads into the splitter and attached "Do Not Disconnect, Voice Line" tags on all the other cables. Are people seriously that stupid? I'm sure there are, but come on Comcast.

Regardless, cable won't work in the rest of the house without severe static because of the reduced signal. This doesn't really bother me that much because I really do everything in my living room. It's just the fact that it "cost" Comcast to have them disconnect an already working service because I wouldn't pay them to "hook-up" something that they already installed prior. Nothing like Comcast being paid twice for service, right?

It may not be related but I've never had a Comcast Tech go out of their way to limit by cable before. I've lived in 3 different homes over the last 12 years and this is the only time I've had a problem with Comcast or a Tech for that matter. I will try the fixes above since Comcast appears to be useless. Do their phone technicians have any requirements for their job? Often times I call there and feel I know more about the problem than they do.

Just want to add... I am in Delaware, have been a Comcast user for 9 or 10 years... because there is no other broadband option where I am at (yet).

This is a consistent problem that I have experienced with Comcast. I have updated modems, routers, lines, etc. It basically seems to come down to the 'luck' on staying connected. I have given up on tech support. I have a process of power cycling modem, router, pc. For the last 3 days, have been dealing with it heavily.

Seems like when ever there is a big ad push in the area (new customer loads?), I am more likely to have these issues. I really hate seeing new ad campains.

There is hope, VIOS is cableing in my area. I wonder if they are any better?

Good luck!

Hi Debra,

I apologize for the trouble. Please email my team at We_can_help@cable.comcast.com. Please be sure to include the telephone number on your account as well as a good contact number for you.

Best,

Detreon Roberts
Comcast Connect

Hi All,

I have the very same problem with similar timing and I have followed all the steps that have been recommended previously. I live in Northern Florida. I run Windows Vista Home Premium 64 bit, on a x58 MB with a I7 processor, 6 Gb of 1600 Mhz Ram, 1 Tb caviar black HD, D-link 802.n wireless adapter, Netgear wireless gigabit router WNR854T, and Motorola SB 6120 cable modem. All have the latest firmware. Comcast has been courteous but no help so far however I did just email the address in the last post and my fingers and toes are crossed. Next I become a cable technician and start tearing into their stuff.

Tom

Hi all again,

It appears Comcast may have figured this problem out. For the past day and a half I have had no drops. Understand thats down from every 20 to 40 minutes. What a difference. I ran the suggested ping and 100% successful pings at average 63 ms. I ran the speed test and 13,345 kb/s down, 3,566 kb/s up. I would like to thank all the bloggers including and especially the COMCAST ones. I don't know what you did but it worked.

Tom

Oh my goodness! Lol I've had comcast forever and I've never had so many problems before now. I didn't read all of the posts I'll add because I have two little girls that need my attention.

I play online games to pass time while I watch my little girls. I have phone, internet, and cable. However since I added the phone to my services and upgraded my cable internet and phone as well I've had drops from my internet and phone like crazy. I've been so angry with comcast because they seem to care sooo little about what I'm experiancing. I pay about 140 dollars a month and yet they can't fix the problem.

I've had several tech's come to my house and been on the phone (when it's up which seems very random about dropping or "Gargling talk" on my end) many many times with comcast support. Generally their very rude and not helpful. They can't see what's wrong since apparently my singal strength is just fine. It's gotten to the point where I've been keeping a log of the times my internet drops along with my phone (their both connected to the modem.) I've had a tech come out and replace the modem as well, made no differance and infact made it worse.

Internet/Phone dropping
Oct12 1.didn't write down time
2. 1:30pm
3. 2:23pm
4. 2:43pm
restarted router/modem
5. 2:54pm (checked modem first two lights on 3rd blinking)
Called comcast when modem was back up left message.
6. 6:04pm
7. 7:37pm
Oct13 1. 3:33pm
2. 3:35pm
3: 3:47pm
Stopped using internet due to frustration.Husband had non stop disconnecting after I got frustrated and gave up.
4. 6:24pm "Internal Server Error"
Oct14 1.4:55pm
Oct15 1. 11:40am
2. 11:58am
3. 12:28
4. 2:13 Plugged modem stright into my computer so no router would be cause of the problem.
5. 3:41pm
6. 5:06pm
7. 7:11pm
Sooo you can see why this is getting frustrating? Lol they keep telling me nothing seems to be wrong. I'm getting very ticked off. Because obviously something is wrong...lol. Btw comcast never called me back from that phone call I gave them. I just don't see why I should keep paying for a service I'm obviously am NOT being provided the way that I should be. Oh and the upgrade I got on my internet was for faster internet connection..lol. Doesn't seem to be working

Btw they blamed my phone for not being compatable so I replaced it and it didn't make anything better.