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Forum Discussion
jamesli
Jul 24, 2016Aspirant
C3000 Wifi Drop-off Issue
TL;DR: The wifi drops off completely and doesn't link back to the Internet at least once a day, no power issues, no connectivity issues.
I have the C3000 DOCSIS 3.0 cable gateway on Comcast Xfinity, I'm not using a cable splitter or any other kind of product, my regular wifi download speed exceeds 15Mbps (occassionally goes up to 25Mbps). My wired connectivity hardly drops, but my wifi function has been malfunctioning at least once a day. A powercycle is the only way to fix this issue, and all my settings are under factory default setting, no modifications were done on the modem.
Here's what I did to triage the issue:
1. Changing channels after reboot - doesn't work, every channel drops off once in a while
2. Checked power issue, please see following chart for power levels:
Downstream Bonded Channels | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Upstream Bonded Channels | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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3. Checked logs:
[Internet connected] IP address: 50.161.98.113 | 1 | Sun Jul 24 09:27:57 2016 | 0.0.0.0:0 | 0.0.0.0:0 |
[DHCP IP: 192.168.0.12] to MAC address a0:99:9b:1e:3b:7b | 1 | Sun Jul 24 09:27:48 2016 | 0.0.0.0:0 | 0.0.0.0:0 |
[DHCP IP: 192.168.0.16] to MAC address 60:5b:b4:0a:43:b5 | 1 | Sun Jul 24 09:27:47 2016 | 0.0.0.0:0 | 0.0.0.0:0 |
[Time synchronized with ToD server] | 1 | Sun Jul 24 09:27:43 2016 | 0.0.0.0:0 | 0.0.0.0:0 |
[DHCP IP: 192.168.0.12] to MAC address a0:99:9b:1e:3b:7b | 1 | Thu Jan 01 00:00:53 1970 | 0.0.0.0:0 | 0.0.0.0:0 |
[DHCP IP: 192.168.0.16] to MAC address 60:5b:b4:0a:43:b5 | 1 | Thu Jan 01 00:00:52 1970 | 0.0.0.0:0 | 0.0.0.0:0 |
[DHCP IP: 192.168.0.12] to MAC address a0:99:9b:1e:3b:7b | 1 | Thu Jan 01 00:00:42 1970 | 0.0.0.0:0 | 0.0.0.0:0 |
[DHCP IP: 192.168.0.16] to MAC address 60:5b:b4:0a:43:b5 | 1 | Thu Jan 01 00:00:40 1970 | 0.0.0.0:0 | 0.0.0.0:0 |
[DHCP IP: 192.168.0.10] to MAC address 00:18:4d:ff:ff:07 | 1 | Thu Jan 01 00:00:32 1970 | 0.0.0.0:0 | 0.0.0.0:0 |
[Initialized, firmware version: V2.02.08] | 1 | Thu Jan 01 00:00:31 1970 | 0.0.0.0:0 | 0.0.0.0:0 |
[DHCP IP: 192.168.0.11] to MAC address c0:ee:fb:33:c9:fc | 1 | Sat Jul 23 18:15:06 2016 | 0.0.0.0:0 | 0.0.0.0:0 |
[DHCP IP: 192.168.0.16] to MAC address 60:5b:b4:0a:43:b5 | 1 | Sat Jul 23 18:15:03 2016 | 0.0.0.0:0 | 0.0.0.0:0 |
[Internet connected] IP address: 50.161.98.113 | 1 | Sat Jul 23 18:15:02 2016 | 0.0.0.0:0 | 0.0.0.0:0 |
[DHCP IP: 192.168.0.14] to MAC address 6c:ad:f8:7f:49:bf | 1 | Sat Jul 23 18:15:00 2016 | 0.0.0.0:0 | 0.0.0.0:0 |
[DHCP IP: 192.168.0.16] to MAC address 60:5b:b4:0a:43:b5 | 1 | Sat Jul 23 18:14:52 2016 | 0.0.0.0:0 | 0.0.0.0:0 |
[DHCP IP: 192.168.0.14] to MAC address 6c:ad:f8:7f:49:bf | 1 | Sat Jul 23 18:14:49 2016 | 0.0.0.0:0 | 0.0.0.0:0 |
[Time synchronized with ToD server] | 1 | Sat Jul 23 18:14:46 2016 | 0.0.0.0:0 | 0.0.0.0:0 |
[DHCP IP: 192.168.0.16] to MAC address 60:5b:b4:0a:43:b5 | 1 | Thu Jan 01 00:00:53 1970 | 0.0.0.0:0 | 0.0.0.0:0 |
[DHCP IP: 192.168.0.11] to MAC address c0:ee:fb:33:c9:fc | 1 | Thu Jan 01 00:00:47 1970 | 0.0.0.0:0 | 0.0.0.0:0 |
[DHCP IP: 192.168.0.16] to MAC address 60:5b:b4:0a:43:b5 | 1 | Thu Jan 01 00:00:41 1970 | 0.0.0.0:0 | 0.0.0.0:0 |
[DHCP IP: 192.168.0.10] to MAC address 00:18:4d:ff:ff:07 | 1 | Thu Jan 01 00:00:32 1970 | 0.0.0.0:0 | 0.0.0.0:0 |
[Initialized, firmware version: V2.02.08] | 1 | Thu Jan 01 00:00:30 1970 | 0.0.0.0:0 | 0.0.0.0:0 |
[DHCP IP: 192.168.0.12] to MAC address a0:99:9b:1e:3b:7b | 1 | Fri Jul 22 21:02:16 2016 | 0.0.0.0:0 | 0.0.0.0:0 |
[DHCP IP: 192.168.0.11] to MAC address c0:ee:fb:33:c9:fc | 1 | Fri Jul 22 21:02:03 2016 | 0.0.0.0:0 | 0.0.0.0:0 |
[DHCP IP: 192.168.0.16] to MAC address 60:5b:b4:0a:43:b5 | 1 | Fri Jul 22 21:01:59 2016 | 0.0.0.0:0 | 0.0.0.0:0 |
[DHCP IP: 192.168.0.14] to MAC address 6c:ad:f8:7f:49:bf | 1 | Fri Jul 22 21:01:49 2016 | 0.0.0.0:0 | 0.0.0.0:0 |
[DHCP IP: 192.168.0.16] to MAC address 60:5b:b4:0a:43:b5 | 1 | Fri Jul 22 21:01:48 2016 | 0.0.0.0:0 | 0.0.0.0:0 |
[DHCP IP: 192.168.0.20] to MAC address 38:71:de:db:04:65 | 1 | Fri Jul 22 21:01:41 2016 | 0.0.0.0:0 | 0.0.0.0:0 |
[Internet connected] IP address: 50.161.98.113 | 1 | Fri Jul 22 21:01:40 2016 | 0.0.0.0:0 | 0.0.0.0:0 |
[DHCP IP: 192.168.0.14] to MAC address 6c:ad:f8:7f:49:bf | 1 | Fri Jul 22 21:01:38 2016 | 0.0.0.0:0 | 0.0.0.0:0 |
[DHCP IP: 192.168.0.16] to MAC address 60:5b:b4:0a:43:b5 | 1 | Fri Jul 22 21:01:37 2016 | 0.0.0.0:0 | 0.0.0.0:0 |
[DHCP IP: 192.168.0.11] to MAC address c0:ee:fb:33:c9:fc | 1 | Fri Jul 22 21:01:32 2016 | 0.0.0.0:0 | 0.0.0.0:0 |
[DHCP IP: 192.168.0.20] to MAC address 38:71:de:db:04:65 | 1 | Fri Jul 22 21:01:30 2016 | 0.0.0.0:0 | 0.0.0.0:0 |
[DHCP IP: 192.168.0.14] to MAC address 6c:ad:f8:7f:49:bf | 1 | Fri Jul 22 21:01:27 2016 | 0.0.0.0:0 | 0.0.0.0:0 |
[Time synchronized with ToD server] | 1 | Fri Jul 22 21:01:26 2016 | 0.0.0.0:0 | 0.0.0.0:0 |
I've marked the time synchronize event to red because these are the exact time that my wifi function stopped working. I think this somehow indicates that either the initialization (causing the system time to revert back to 1970) or the synchronizing event are the root cause of drop offs.
4. Last, you can see from the event log that it indicates a time sychronization failure, timestamp is always at 1970 since the modem was initialized back to 1970:
1970-1-1, 00:00:31 | Critical (3) | SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=2c:30:33:ba:b2:a8;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; |
1970-1-1, 00:00:38 | Critical (3) | No Ranging Response received - T3 time-out;CM-MAC=2c:30:33:ba:b2:a8;CMTS-MAC=00:01:5c:62:1c:58;CM-QOS=1.0;CM-VER=3.0; |
1970-1-1, 00:00:32 | Critical (3) | SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=2c:30:33:ba:b2:a8;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; |
1970-1-1, 00:00:39 | Critical (3) | No Ranging Response received - T3 time-out;CM-MAC=2c:30:33:ba:b2:a8;CMTS-MAC=00:01:5c:62:1c:58;CM-QOS=1.0;CM-VER=3.0; |
1970-1-1, 00:00:31 | Critical (3) | SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=2c:30:33:ba:b2:a8;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; |
1970-1-1, 00:00:38 | Critical (3) | No Ranging Response received - T3 time-out;CM-MAC=2c:30:33:ba:b2:a8;CMTS-MAC=00:01:5c:62:1c:58;CM-QOS=1.0;CM-VER=3.0; |
1970-1-1, 00:00:31 | Critical (3) | SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=2c:30:33:ba:b2:a8;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; |
In all, I think this is a quality issue. I purchased this modem through Amazon in March, and this issue has been very persistent throughout my usage. I have ruled out Xfinity issues and my connected device issues. I hope Netgear can come up with some kind of a fix to this as this is proven to be a problem for many consumers.
3 Replies
- DarrenMSr. NETGEAR Moderator
jamesli
You may want to contact our Netgear support for this if you think is a issue with your modem they will be able to troubleshoot with you and figure out if its a faulty unit or not and find a solution if you are still under warranty.
https://www.netgear.com/support/contact.aspx?cid=wmt_netgear_organic
DarrenM
- ericpeters0nAspirant
Same problem.
The reply above is not a solution...- dolittle63Aspirant
I am having the same problem. I cant keep my iphones in the house or my nest thermostats to stay connected. the hard wired connection is perfect.