c3700 connection issue - only able to access a few websites

[ng678]

I came back from vacation to find that my c3700 would only access certain websites (Facebook, Gmail, Comcast, Wikipedia, and so on) but not the rest of the internet (Amazon, Reddit, CNN, Evernote).

After troubleshooting with Comcast (including trying Google's DNS, and resetting the router/modem to factory settings) I borrowed a Comcast device and was able to access everything fine that way (suggesting no issue with my cables or wiring).

My firmware version is V1.01.11, and I've posted a sample from the event log and my up/down info below.

Any ideas as to what could cause this issue?

Startup Procedure

Procedure	Status	Comment
Acquire Downstream Channel	693000000 Hz	Locked
Connectivity State	OK	Operational
Boot State
Configuration File
Security	Enabled	BPI+

---

Downstream Bonded Channels

Channel	Lock Status	Modulation	Channel ID	Frequency	Power	SNR	Correctables	Uncorrectables
1		QAM256		693000000 Hz	7.9 dBmV	38.6 dB	0	0
2		QAM256		651000000 Hz	8.8 dBmV	38.6 dB	0	0
3		QAM256		657000000 Hz	8.6 dBmV	38.8 dB	0	0
4		QAM256		663000000 Hz	8.2 dBmV	38.5 dB	0	0
5		QAM256		669000000 Hz	8.4 dBmV	39 dB	4	0
6		QAM256		675000000 Hz	8.4 dBmV	39.2 dB	0	0
7		QAM256		681000000 Hz	8 dBmV	38.6 dB	5	0
8		QAM256		687000000 Hz	7.9 dBmV	38.6 dB	0	0

---

Upstream Bonded Channels Channel Lock Status US Channel Type Channel ID Symbol Rate FrequencyPower 1 ATDMA 5120 Ksym/sec36500000 Hz39 dBmV

2 ATDMA 5120 Ksym/sec30100000 Hz39 dBmV

3 ATDMA 5120 Ksym/sec23700000 Hz39 dBmV

4 Unknown 0 Ksym/sec0 Hz0.0 dBmV

Event Log

2015-8-14, 16:58:25.0	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=6c:b0:ce:2d:d2:38;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
1970-1-1, 00:00:33.0	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=6c:b0:ce:2d:d2:38;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;

[ng678]

I spoke to support over the phone and they seemed to think that this was an issue with the router/modem settings, but the person I spoke seemed to be reading off a script and wasn't able to tell me what firmware I should be running.

It also doesn't make sense since I hadn't changed any setting when the issue first popped up.

Does anyone have any ideas please? Support has been very frustrating.

[DarrenM]

Hello ng678

Have a couple questions for you 

• Is issue happening on both wired or wireless?
• Is issue happening on all devices or just one?
• Try a different browser and reset the Internet history and cache.
• Make sure Advanced>Security> Block sites is configured to Never.
• Were you using parental control feature previously.

DarrenM

[ng678]

This issue occurs for both wired and wireless, on multiple devices (including a desktop windows 7, an iphone, and a macbook), also with multiple browsers on these devices.

No sites are currently blocked, and I have not ever used parental controls (although I cannot tinker with parental controls as doing so requires accessing the internet).

[Reckoner]

I share your pain. I'm having similar problems and the Netgear logs indicate the trouble began recently.

Netgear customer support has been almost useless.

[ng678]

I've done some googling and seen people having similar issues with a variety of netgear devices in the last three months (perhaps a firmware issue?) but none of them posted a resolution other then trying another vendor (and I've had similar struggles with customer support).

I'm happy to help with what I've learned so far though!

Did you try another device? I borrowed a friends and it did get a connection, so that's why I'm pretty sure the issue is with my netgear device. 

[Reckoner]

I am able to connect to websites most of the time, although they do frequently "hang" or disconnect. My biggest problem seems to be that my Netgear modem cannot maintain the accurate/correct time and date. This causes me trouble when trying to access secure sites or when trying to download secure packages.

I have finally convinced Netgear that the problem is a latent defect in the unit, or possibly the result of a hack due to known security vulnerabilities. I'm sending my modem back for replacement.

[ng678]

How did you convince them of that?

When I called the help line they insisted it was a software issue and wouldn't go off script at all.

Someone escalated me to higher level support, but they just walked me through the same things again, asked for some screenshots, and didn't get back to me.

I'm starting to get very frustrated. 😞

[ng678]

So I used my RMA to replace my malfunctioning device, I don't know if they poked it with a stick and sent it back, but my new one's wireless doesn't seem to work for ANY websites (although the wired connection now works).

Comcast verified that it is provishined fine and such, but I have no idea why my fresh device is having issues. 

[DarrenM]

Hello ng678 

Are you able to connect to the wireless and it say connected to the internet but you can not access a website? Maybe its a strange DNS issues try to go to 74.125.25.103 in your web browser this is the ip to www.google.com Let me know what happens.

DarrenM

[ng678]

I can't connect to the wireless, and I get full bars.

When I try and put in a website, it doesn't load - chrome does say "connection refused" specifically.

If I put in "74.125.25.103" it doesn load, but the address in the address bar does change to "google.com" but that may be because I've gone to google before.

(this is all on a macbook)

My PS4 seems to think it may be a DNS issue, but it's not exactly the best diagnosic measure. 

[DarrenM]

We can try something to test if it is a DNS issue if you log into your router and then click on advanced-setup-internet setup then Click use these DNS servers try to enter googles dns for the primary DNS use 8.8.8.8 and for the secondary use 8.8.4.4 shouldnt need a third one then test if any thing will connect to a website. This will rule out if its DNS related or not. 

DarrenM

[ng678]

Changing to Google DNS seems to fix the issue. Thank you!

Remind me, what would cause DNS issues like that?

[DarrenM]

The Dns is provided by the ISP its a server they run for all there customers so when you type websites in such as www.google.com it will point your pc to the proper ip address and connect to that website. glad that worked for you may want to contact them and inform them something is wrong with the DNS.

DarrenM

[Reckoner]

If you need to do some snooping around your network, there's a great available for iPhone and iPad. It's called Fing. It's invaluable for seeing each device's IP address and MAC address and channel. I'm pretty sure it's free, but it's worthwhile.  Hope you're able to sort things out soon.