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I have Cox Cable in San Diego County. Our connection drops three or four times a day and these are the errors:

2006-08-31 12:35:38 critical DHCP WARNING - Non-critical field invalid in response.
2006-08-31 12:35:26 critical Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 timeout
2006-08-31 12:34:54 critical Started Unicast Maintenance Ranging - No Response received - T3 time-out
2006-08-31 12:04:27 critical DHCP WARNING - Non-critical field invalid in response.
2006-08-31 12:04:21 critical No Ranging Response received - T3 time-out
2006-08-31 12:04:16 critical Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 timeout
2006-08-31 12:03:43 critical Started Unicast Maintenance Ranging - No Response received - T3 time-out
2006-08-30 22:12:26 error ToD request sent- No Response received
2006-08-30 22:12:25 critical DHCP WARNING - Non-critical field invalid in response.
2006-08-30 22:12:21 critical DHCP FAILED - Discover sent, no offer received
2006-08-30 22:12:02 critical No Ranging Response received - T3 time-out
2006-08-30 22:11:46 critical Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 timeout
2006-08-30 22:11:13 critical Started Unicast Maintenance Ranging - No Response received - T3 time-out
2006-08-30 21:17:59 critical DHCP WARNING - Non-critical field invalid in response.
2006-08-30 21:17:52 critical No Ranging Response received - T3 time-out
2006-08-30 21:17:46 critical Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 timeout
2006-08-30 21:17:14 critical Started Unicast Maintenance Ranging - No Response received - T3 time-out
2006-08-30 12:37:32 critical DHCP WARNING - Non-critical field invalid in response.
2006-08-30 12:37:24 critical Init RANGING Critical Ranging Request Retries exhausted
2006-08-30 12:37:24 critical No Ranging Response received - T3 time-out
2006-08-30 12:36:47 critical Init RANGING Critical Ranging Request Retries exhausted
2006-08-30 12:36:47 critical No Ranging Response received - T3 time-out
2006-08-30 12:36:16 critical Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 timeout
2006-08-30 12:35:43 critical Started Unicast Maintenance Ranging - No Response received - T3 time-out
2006-08-30 12:35:27 critical No Ranging Response received - T3 time-out
2006-08-30 12:35:20 critical Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 timeout
2006-08-30 12:34:47 critical Started Unicast Maintenance Ranging - No Response received - T3 time-out
2006-08-30 12:01:16 error ToD request sent- No Response received
2006-08-30 12:01:15 critical DHCP WARNING - Non-critical field invalid in response.
2006-08-30 12:01:03 critical Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 timeout
2006-08-30 12:00:31 critical Started Unicast Maintenance Ranging - No Response received - T3 time-out
2006-08-30 09:50:55 warning DHCP RENEW WARNING - Field invalid in response

cox came out and told me that everything looks good as far as they're concerned. What now? I spoke with Linksys but they act like they're clueless.

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  • Latest Post Latest Post by egnilk66

Dani AI

Generated

Given ’s notes that a Cox tech saw “nothing” and that swapping the Linksys didn’t change the behavior, the pattern points away from the LAN/router and toward DOCSIS/line-level problems (ranging/timeouts and upstream noise) at the modem/CMTS side. (volpefirm.com)

T3/T4-style events are DOCSIS ranging/maintenance timeouts: a T3 happens when the modem’s ranging requests get no reply and it resets its cable interface; a T4 means the modem got a broadcast maintenance response but no unicast opportunity to complete ranging. DHCP warnings commonly appear after the modem loses registration — they are usually secondary to the DOCSIS disconnects. (volpefirm.com)

Practical isolation steps (do in order, document results):

  • Test with a single device connected directly to the modem (router removed) and watch the modem’s status/logs for drops.
  • Move the modem to the house’s main incoming coax (before any splitters) and use a short, known-good RG‑6 cable and clean connectors.
  • Remove or replace any passive splitters with a data-rated splitter (or temporarily bypass them).
  • Record downstream/upstream power and SNR from the modem status page (take dated photos). Typical acceptable downstream and upstream ranges and SNR guidance are published by manufacturers — use those readings to prove the problem to the ISP. (help.motorolanetwork.com)

What to request from Cox: have the support agent run a CMTS-level check for the modem MAC (look for upstream noise/MER, Rx power, and reset/count history), inspect the drop/tap/amplifier, and escalate to field maintenance or a node/port swap if upstream noise or marginal power is shown. If the user already replaced the modem and the same DOCSIS ranging failures persist, insist that the plant (drop/tap/node) be checked rather than replacing more customer equipment. (pickmymodem.com)

Summary: these are classic cable‑plant symptoms. The next useful evidence is a short log/screenshot of the modem’s signal stats and a test with the modem at the incoming feed (no splitters) so the provider can see the true upstream/downstream health.

Member Avatar for egnilk66

I just spoke with Linksys and they told me that a hard reset is one of two suggestions. If that doesn't work the other suggestion is to replace it. Great!

Member Avatar for egnilk66

I replaced it and am getting the same errors!

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