Home Networking / Router / & WiFi Gateway Help

[NS_TX]

This is a recent issue, so not sure what has changed. I've been using my comcast modem with my Airport Extreme for a while now without any issues. Recently, I keep getting an inconsistent connection with it. Comcast reports my connection is up, but my actual internet connection constantly goes in and out. I've done it all, power-cycled the modem, reset the router, you name it. I even went ahead and changed the following settings on it:

- DNS servers were changed to 208.67.222.222 and 208.67.220.220

- DHCP beginning and ending address was changed to 192.168.1.2 to 192.168.1.200

The airport is a 2nd generation airport extreme 802.11n, version 7.6.1

What else can I do? Is this something I can fix? I'm just at my wits end right now. Just can't find a solid solution. Appreciate any help.  Thank you.

[tbonecopper]

Could you tell us some more information? 

How do you know the internet is going down? Are the signal lights on your modem flashing in the "out of service / halp halp something's wrong" order? Or are you losing Wifi randomly?

if you're on a Windows Computer, is the Wifi signal showing a error? Or if you're on a Mac, is the Airport icon turning grey (instead of solid black)?

Apple Airport icon: http://tinypic.com/r/nd3bz6/6

Windows 7 Wifi icon: http://tinypic.com/r/2z9mujp/6

Or, is the icon staying normal, but you're getting "This page can't be displayed" style errors in your web browser?

Additionally, you can sign up for a free pingdom account here: http://www.pingdom.com/    Pingdom will let you monitor the actual uptime of your internet, regardless of how your router is feeling. You'll need your comcast IP address, which most likely changes from time to time (usually not on a weekly basis) , which you can get at www.ipchicken.com  - pingdom will use that to gauge your uptime on your connection. 

I'm assuming you're connecting over wifi - have you tried changing the channel in your Airport Utility? It's possible there are other wifi networks in the area who are using the same channel you're using, which may knock you offline. Lots of interference up there!

If it's happening on wifi, have you used an ethernet cable from your computer > the router for a little bit, to replicate the issue?

[EG]

OP. What is the exact make and model number of the :Comcast modem" ? What do the modem's signal stats look like ? Try getting them here; http://192.168.100.1 or here http://10.0.0.1

Please post the *Downstream Power Level*, the *Upstream Power Level*, and the *SNR* (Signal to Noise Ratio) numbers.

[Jcwell]

07-13-2012 12:05 PM

With my modem (Motorola SB 6120) , the SNR Ratio is 38 dB.

"Bonding Channel Value"  2, 3, 4, and 7 Downstream power level  is 4, 3, 3, and 4dBmV (respectively). 

"Bonding Channel Value"  2, 1, 3, Upstream power level  is 48, 47, and 49dBmV (respectively). 

The modem that does work with wireless, same router, that Comcast is once again renting to me, is a Ubee D3.0.

Jennifer, State College PA

[Jcwell]

With my modem (Motorola SB 6120) , the SNR Ratio is 38 dB.

"Bonding Channel Value"  2, 3, 4, and 7 Downstream power level  is 4, 3, 3, and 4dBmV (respectively). 

"Bonding Channel Value"  2, 1, 3, Upstream power level  is 48, 47, and 49dBmV (respectively). 

The modem that does work with wireless, same router, that Comcast is once again renting to me, is a Ubee D3.0.

Jennifer, State College PA

[EG]

As was previously asked by another poster, what are the indicator lights doing on the modem when this happens ?

[Jcwell]

Allindicator lights on; doing what they ought to, internet connectivity flashes.

[EG]

Are you the original poster ? I was asking the OP (Original Poster). You have your own ongoing help thread.

[NS_TX]

Hi;

Will get you this information when I get home today (currently at work). But to give you an idea of what is going on:

- The wireless icon on my devices show connectivity (laptop, smartphone, etc..)

- The light on my router is green (on the airport that means there are no issues with the connection, etc..)

I'm suspecting it's either the modem or the router that is acting up. Will get you those numbers tonight pertaining to my comcast modem.

In general, when you connect the modem to the router, are there any settings that I should manually set, or does the router automatically get those from the modem? This information is typically the following:

- DNS numbers and addresses

- The DHCP range ( I have a choice of 192.168... or 10.0...).

(i'm just not sure if I need to personally set this information in my airport extreme router)

Appreciate the help.

NS

[NS_TX]

---

tbonecopper wrote:

Could you tell us some more information? 

How do you know the internet is going down? Are the signal lights on your modem flashing in the "out of service / halp halp something's wrong" order? Or are you losing Wifi randomly?

if you're on a Windows Computer, is the Wifi signal showing a error? Or if you're on a Mac, is the Airport icon turning grey (instead of solid black)?

Apple Airport icon: http://tinypic.com/r/nd3bz6/6

Windows 7 Wifi icon: http://tinypic.com/r/2z9mujp/6

Or, is the icon staying normal, but you're getting "This page can't be displayed" style errors in your web browser?

Additionally, you can sign up for a free pingdom account here: http://www.pingdom.com/    Pingdom will let you monitor the actual uptime of your internet, regardless of how your router is feeling. You'll need your comcast IP address, which most likely changes from time to time (usually not on a weekly basis) , which you can get at www.ipchicken.com  - pingdom will use that to gauge your uptime on your connection. 

I'm assuming you're connecting over wifi - have you tried changing the channel in your Airport Utility? It's possible there are other wifi networks in the area who are using the same channel you're using, which may knock you offline. Lots of interference up there!

If it's happening on wifi, have you used an ethernet cable from your computer > the router for a little bit, to replicate the issue?

---

Wifi is being lost randomly. My PC which is hardwired to the router is also losing connection randomly, so it's not entirely related to the wireless ONLY. I have my airport channel on AUTO. The airport icon on my laptops and phones always show full connectivity even when the connection is out. That's why I was initially asking if I need to change anything manually on my airport to get things more in tune with the modem (like changing the DNS settings or the DHCP range).

[EG]

---

NS_TX wrote:

In general, when you connect the modem to the router, are there any settings that I should manually set, or does the router automatically get those from the modem? 

---

If the router is set for auto configuration / DHCP, there is nothing you need to do for the WAN settings.

[NS_TX]

---

EG wrote:

OP. What is the exact make and model number of the :Comcast modem" ? What do the modem's signal stats look like ? Try getting them here; http://192.168.100.1 or here http://10.0.0.1

Please post the *Downstream Power Level*, the *Upstream Power Level*, and the *SNR* (Signal to Noise Ratio) numbers.

---

Modem model: Ambit U10C018

Downstream power level: -6.4 dBmV

Upstream power level: 36.7 dBmV

SNR: 31.3 dB

I checked out the even log. Lots of critical messages. These were listed as critical:

- Unicast Ranging Received Abort Response - Re- initializing MAC

- DCC aborted unable to communicate on new upstream channel

- Started Unicast Maintenance Ranging - No Response received - ...

- No Ranging Response received - T3 time-out

- SYNC Timing Synchronization failure - Failed to acquire QAM/Q...

-
And a warning message that constantly showed up:

DHCP WARNING - Non-critical field invalid in response ;CM-MAC...

Hope these help to track this problem down.  Thanks.

[FF100]

Hello.

This message string stopped back in July with no clear solution posted. I have been having the same problem for the last two months. Before that there was no problem and there has been no equipment change. I am using the ARRIS modem provided by Comcast and the Apple Airport. I am losing my WIFI connection almost daily. The modem lights stay green and show properly. The Airport light stays green. My WIFI signal on my Mac grays out and a dialog box appears listing other networks that are available. The PCs on the network don't get any message. They just can't establish a connection even though the computer says network connection established. The problem is usually corrected by unplugging the Airport and plugging it back in. Very frustrated. Would appreciate any available help.

Thanks, FF100

[winevines]

Same here.  I just bought a new router today out of total frustration.  Worked fine 2 days ago before COmcast internet outage and alleged upgrade of service.

$175 out the window

[elee888]

Yes, I'm having the same problem as well. It gets really slow sometimes and sometimes it just gives up loading pages.  I thought that I had a bad router, but I'm on my 2nd airport extreme.  I did try something else last week.  Basically, I had my laptop connected to the modem via ethernet and had the laptop share the connection wireless to my other devices.  I left it that way for over a week and the problem didn't show up.  Now, I plug my airport extreme back in and the first few days were good and now its going to down the drain again.  I tried changing the DNS servers as well, but that didn't really help either.  What's really weird is that this just started to happen a few months ago.  I live in a townhome complex, I wonder if neighboors moving in and getting comcast are messing something up...   :\

[smripley]

I am also experciening similar issues.

I have two airport extremes (one attached to the comcast modem) and the other acting as a bridge via ethernet.

Attaching direct to the modem - no issue.

I disconnected the bridge airport and am running directly on the airport attached to the modem. I am experimenting with a computer using ethernet and one using wireless and I continue to experience drops in service.

I am using google DNS by the way - doubt this matters.

[Baric]

"Drops in service" is pretty vague, care to provide specifics?  Only wired or wireless?  During this "drop", what exactly happens?  Can you still talk to the router itself (ie. is the aiport Utility letting you display and open the settings for your AE?).  Can you open your modem's status page?  What are the router and modem status readings at the time of the problem?  What about your computer?  what kind of computer and what OS?  What tcp/ip settings are you using in the computer.

If the issue is wireless only, try changing the wireless channel on the router.

While there's nothing wrong with using Google's DNS, I would recommend against it.  The Comcast DNS servers are really pretty good and in general respond faster to external DNS servers.  Also, DNS issues do tend make a connection look like it "dropped" since name resolution is not working.  I suggest you switch back to the automatically assigned Comcast DNS servers in your area, or use 75.75.75.75 and 75.75.76.76.

I use an Apple Time Capsule here, which is the same as an Airport Extreme with a built in hard drive.  It works wonderfully.  I use it with wired Win7 and Linux systems, as well as wireless MacBook Pros', iPhones, iPads, PS3, etc.

[Tcsekhar]

I had the same problem. This started happening only after I switched to docsis 3.0 modem. I had to reboot the router every time to get back my 25MBPS. It remains at 25MBPS for 6 to 12 hrs and again goes into 1 Mbps. I thought this could be my airport extreme. Hence I made it a bridge and inserted a Cisco wired router to manage the IP addresses. But the same problem persists. I have to reset my Cisco router every 6 to 12 hrs to retain a 25mbps connection.

Now I have a bookmark to the router reboot page

Startup Procedure Procedure Status Comment Acquire Downstream Channel 675000000 Hz Locked Connectivity State OK Operational Boot State OK Operational Configuration File OK   Security Enabled BPI+
Downstream Bonded Channels Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables 1 Locked QAM256 2 675000000 Hz 11.7 dBmV 39.9 dBmV 0 0 2 Locked QAM256 1 669000000 Hz 11.7 dBmV 39.8 dBmV 0 0 3 Locked QAM256 3 681000000 Hz 12.0 dBmV 39.9 dBmV 0 0 4 Locked QAM256 4 687000000 Hz 12.1 dBmV 39.9 dBmV 0 0 5 Locked QAM256 5 693000000 Hz 12.5 dBmV 39.9 dBmV 0 0 6 Locked QAM256 6 699000000 Hz 12.3 dBmV 39.9 dBmV 0 0 7 Locked QAM256 7 705000000 Hz 12.5 dBmV 39.8 dBmV 0 0 8 Locked QAM256 8 711000000 Hz 12.6 dBmV 39.4 dBmV 0 0
Total Correctables Total Uncorrectables 0 0

Upstream Bonded Channels Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power 1 Locked ATDMA 10 5120 Ksym/sec 36400000 Hz 28.5 dBmV 2 Locked ATDMA 11 5120 Ksym/sec 29500000 Hz 27.8 dBmV 3 Locked TDMA 12 2560 Ksym/sec 24200000 Hz 27.0 dBmV 4 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
CM IP Address CM IP Address 73.44.74.57

[EG]

Hello Tcsekhar

You were replied to here;

http://forums.comcast.com/t5/Basic-Internet-Connectivity-And/Re-Why-am-I-having-to-reset-my-router-d...

In future, please keep a single concern in a single thread / topic, thanks.