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Forum Discussion
Connection issues with c6250
My router is having intermittent connection issues. Periodically it'll just cut out and I won't have a connection for 5 minutes or so before it comes back. On the bottom, it's labeled as a Netgear AC1600 Wi-Fi Cable Modem Router, model C6250. I've had it since late 2018 and it's worked fun up until several months ago when the issues started appearing. I've posted a copy of the event log from the last couple days. I don't understand any of it, so any help with it would be appreciated.
| 2024-6-12, 09:15:54 | Warning (5) | Dynamic Range Window violation |
| 2024-6-12, 09:15:36 | Critical (3) | Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 2024-6-12, 08:59:59 | Warning (5) | Dynamic Range Window violation |
| 2024-6-12, 08:59:58 | Notice (6) | WiFi Interface [wl0] set to Channel 6 (Side-Band Channel:N/A) - Reason:INTERFERENCE |
| 2024-6-12, 08:59:58 | Warning (5) | Dynamic Range Window violation |
| 2024-6-12, 08:59:57 | Critical (3) | Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 2024-6-12, 08:59:55 | Notice (6) | TLV-11 - unrecognized OID;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 2024-6-12, 08:59:55 | Error (4) | Missing BP Configuration Setting TLV Type: 17.9;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 2024-6-12, 08:59:55 | Error (4) | Missing BP Configuration Setting TLV Type: 17.8;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 2024-6-12, 08:59:55 | Error (4) | Missing BP Configuration Setting TLV Type: 17.7;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 2024-6-12, 08:59:55 | Error (4) | Missing BP Configuration Setting TLV Type: 17.6;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 2024-6-12, 08:59:55 | Error (4) | Missing BP Configuration Setting TLV Type: 17.5;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 2024-6-12, 08:59:55 | Error (4) | Missing BP Configuration Setting TLV Type: 17.4;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 2024-6-12, 08:59:55 | Error (4) | Missing BP Configuration Setting TLV Type: 17.3;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 2024-6-12, 08:59:55 | Error (4) | Missing BP Configuration Setting TLV Type: 17.2;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 2024-6-12, 08:59:55 | Error (4) | Missing BP Configuration Setting TLV Type: 17.1;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 1970-1-1, 00:00:39 | Warning (5) | DHCP WARNING - Non-critical field invalid in response ;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.0;CM-VER=3.0; |
| 1970-1-1, 00:00:36 | Notice (6) | Honoring MDD; IP provisioning mode = IPv4 |
| 1970-1-1, 00:00:31 | Notice (6) | WiFi Interface [wl1] set to Channel 153 (Side-Band Channel:N/A) - Reason:INIT |
| 1970-1-1, 00:00:31 | Notice (6) | WiFi Interface [wl0] set to Channel 11 (Side-Band Channel:N/A) - Reason:INIT |
| 1970-1-1, 00:00:29 | Critical (3) | SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; |
| 2024-6-12, 06:36:31 | Critical (3) | Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 2024-6-12, 06:35:41 | Critical (3) | 16 consecutive T3 timeouts while trying to range on upstream channel 2;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 2024-6-12, 06:35:41 | Critical (3) | Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 2024-6-12, 06:34:10 | Critical (3) | Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 2024-6-12, 05:17:55 | Critical (3) | Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 2024-6-12, 03:57:58 | Critical (3) | Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 2024-6-11, 22:12:42 | Critical (3) | SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; |
| 2024-6-11, 22:12:39 | Critical (3) | Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 2024-6-11, 22:04:24 | Critical (3) | Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 2024-6-11, 07:41:14 | Critical (3) | Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 2024-6-11, 07:32:35 | Critical (3) | Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 2024-6-11, 07:16:37 | Critical (3) | 16 consecutive T3 timeouts while trying to range on upstream channel 2;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 2024-6-11, 07:16:37 | Critical (3) | Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 2024-6-11, 07:14:41 | Critical (3) | Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 2024-6-11, 07:10:21 | Critical (3) | Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 2024-6-11, 06:58:23 | Critical (3) | Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 2024-6-11, 06:45:44 | Critical (3) | Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 2024-6-11, 06:27:19 | Critical (3) | Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
| 2024-6-11, 06:26:55 | Critical (3) | Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=3c:37:86:03:5b:90;CMTS-MAC=00:01:5c:87:44:71;CM-QOS=1.1;CM-VER=3.0; |
6 Replies
Please post a copy and paste of the modems connection status page.
https://kb.netgear.com/30007/How-do-I-obtain-the-cable-connection-information-from-a-NETGEAR-cable-modem-modem-routerAny Criticals, Errors or Warnings seen in the event logs needs to be reviewed and resolved by the ISP. Indicates a signal issue on the ISP line up to the modem.
This is what I'm seeing:
Procedure Status Comment Acquire Downstream Channel 597000000 Hz Locked Connectivity State OK Operational Boot State OK Operational Security Enabled BPI+ IP Provisioning Mode Honor MDD honorMdd(4)
Downstream Bonded Channels Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables 1 Locked QAM256 12 597000000 Hz 0.8 dBmV 40.1 dB 36 167 2 Locked QAM256 1 531000000 Hz 1.9 dBmV 40.2 dB 39 139 3 Locked QAM256 4 549000000 Hz 1.6 dBmV 40.3 dB 45 248 4 Locked QAM256 5 555000000 Hz 1.4 dBmV 40.3 dB 21 136 5 Locked QAM256 6 561000000 Hz 1.4 dBmV 40.2 dB 75 312 6 Locked QAM256 7 567000000 Hz 1.4 dBmV 40.2 dB 32 165 7 Locked QAM256 8 573000000 Hz 1.4 dBmV 40.2 dB 62 191 8 Locked QAM256 9 579000000 Hz 1.1 dBmV 40.1 dB 30 187 9 Locked QAM256 10 585000000 Hz 1.1 dBmV 40.1 dB 30 124 10 Locked QAM256 11 591000000 Hz 1 dBmV 40.1 dB 40 164 11 Locked QAM256 13 603000000 Hz 0.7 dBmV 40.1 dB 40 220 12 Locked QAM256 14 609000000 Hz 0.8 dBmV 40.1 dB 45 197 13 Locked QAM256 17 651000000 Hz 0.5 dBmV 40 dB 30 150 14 Locked QAM256 23 687000000 Hz 0.7 dBmV 40 dB 39 175 15 Locked QAM256 24 693000000 Hz 0.7 dBmV 40.1 dB 52 195 16 Locked QAM256 28 717000000 Hz 1.1 dBmV 40.1 dB 39 103 Upstream Bonded Channels (Partial Service) Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power 1 Not Locked Unknown 5 0 Ksym/sec 38000000 Hz 0.0 dBmV 2 Locked ATDMA 6 5120 Ksym/sec 31600000 Hz 45.5 dBmV 3 Not Locked Unknown 7 0 Ksym/sec 25200000 Hz 0.0 dBmV 4 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV Ok power levels are good.
However you have correctables and un-correctables that should be mostly zeros.
Have the ISP check the signal and line quality UP to the modem. Be sure the ISP provisions the modem correctly.
Be sure there are no coax cable line splitters in the between the modem and ISP service box.
Be sure your using good quality RG6 coax cable up to the modem.
Start with removing any amplifiers, signal attenuators, or splitters from the coax.
From there check the line for kinks, damage, moisture in the line.
Check the connectors for improperly made ends, foil touching the copper coax line, loose connections, bad/old/cheap connectors, or corroded connections. Replace them if you do.
Be sure to power OFF the modem for 1 minute then back ON.
https://community.netgear.com/t5/Cable-Modems-Routers/General-info-and-Troubleshooting-for-Cable-Modems/m-p/1530376#M12853
https://kb.netgear.com/24311/Power-level-guidelines-for-a-NETGEAR-cable-modem-router
https://www.duckware.com/tech/solving-intermittent-cable-modem-issues.html
https://highspeed.tips/docsis-events/
Your logs are indicating a line issues.
The problem with the C6250 is that is only a 16x4 modem.
meaning it doesn't cover all the channels and modems like to switch between channels.
So it might look fine now, but not all of them might be.
Start with removing any amplifiers, signal attenuators, or splitters from the coax.
From there check the line for kinks, damage, and moisture in the line.
Check the connectors for improperly made ends, foil touching the copper coax line, loose connections, bad/old/cheap connectors, or corroded connections. Replace them if you do.
If you can, simply connect the modem right where the coax comes into the home. This prevents wiring in the home from being the issue. And some ISPs charge if the wiring issue is in the home. So this helps prevent this.If that doesn't help, the ISP needs to check the line.
You might also check into upgrading at some point. The C6250 is getting older/slower/depreciated. Its coming up on time to upgrade to docsis 3.1 and a different router (prefer modem separate from the router in my experience).
