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Question

Intermittent Modem Connection

  • February 16, 2026
  • 5 replies
  • 55 views
G
The Many
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G34 Modem is intermittent, random bouts of high SNR and connection drops.

 

Modem UI stays blue, web interface says everything is okay, no signs of issues as far as the modem is concerned, but connection to ISP is gone.

Power cycle via pulling the 12v connector usually clears it.  Attempts to reset the router/modem via web interface usually hangs … interface becomes unresponsive.

Logs indicate a link failure - modem can’t get a proper response from the ISP.  But it’s probably the modem RF failing.   Adding a fan to the base of the G34 “resolved” the problem for a while.

 

Room ambient is 72f, air conditioned. Never higher. G34 placed where it gets good air circulation and where my Netgear modem sat for 10 years until it died of old age.  

 

 

    5 replies

    G
    The Many
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    • GWildThe Many
    • Author
    • The Many
    • February 17, 2026

    So no responses from Arris people? How do customers get warranty support ??

     

      S
      Wi-Fi Warriors
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      We apologize for the inconvenience,  

      Could you please confirm your subscribed internet speed plan and the name of your internet service provider?

      When the internet connection drops, does it seem like the gateway is rebooting on its own?

      Also, when the connection is lost on both Ethernet and Wi-Fi, do the Wi-Fi network names disappear as well?

      We recommend checking the cable signal levels within the gateway. If the signal levels are out of the acceptable range, they can lead to the kind of connectivity issues you're experiencing.

      When the signal levels are within the recommended range, your modem can maintain a stable, high-quality connection to the internet

      Please refer to the link below for instructions on how to check your cable signal levels:

      https://arris.my.salesforce-sites.com/consumers/articles/knowledge/G34-G36-Cable-Signal-Levels

      The cable signal levels displayed on the interface page reflect the signals being transmitted by your Internet Service Provider (ISP).

      If you notice that these signal levels are outside the recommended range, we suggest contacting your ISP to have them reviewed and adjusted accordingly.

      While ISPs may have their own approved signal ranges, for this gateway to function properly, the signal levels must align with the acceptable values outlined in the reference article provided.

      SURFboard Community Moderator Team
      G
      The Many
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      • GWildThe Many
      • Author
      • The Many
      • February 21, 2026

      ISP is Sparklight/CableOne.

      Modem loses sync with the ISP, even though it reports all is well with the connection. ISP says SNR drops to zero - the modem’s fault. Modem reports 38dB SNR … apprx +8dBm power levels across 31 channels … yet no real connection and pings to 1.1.1.1 bounce back from modem as “unreachable”.

      Modem just sits there fat dumb and happy and dead to the world -- as if there isn’t a problem.  WiFi and Ethernet are unaffected … just nothing getting through the modem.

      LOG:

      DHCPv6: 72001009-DHCPv6 - No Advertise or Reply Received 1 times 
          02/15/2026 23:56:45    Critical 

      DHCPv6: 72001004-DHCPv6 Provision - 10 Retries Attempted with Last attempt at Sun Feb 15 23:47:26 2026 
          02/15/2026 23:56:45    Critical 

      DHCPv6: 72001004-DHCPv6 Provision - 9 Retries Attempted with Last attempt at Sun Feb 15 23:42:57 2026 
          02/15/2026 23:47:26    Critical 

      UTOPIA: lan.dhcpserver action: old MAC: (Edited private information) IP: 192.168.0.20 VendorClass: android-dhcp-15 
          02/15/2026 23:45:26    Notice 

      DHCPv6: 72001004-DHCPv6 Provision - 8 Retries Attempted with Last attempt at Sun Feb 15 23:40:45 2026 
          02/15/2026 23:42:57    Critical 

      MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 23:38:11    Warning
      No Ranging Response received - T3 time-out;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 23:33:00    Critical
      Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 23:32:49    Critical
      Ranging Request Retries exhausted;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 23:32:49    Critical
      No Ranging Response received - T3 time-out;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 23:32:01    Critical
      Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 23:31:48    Critical
      Ranging Request Retries exhausted;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 23:31:48    Critical
      No Ranging Response received - T3 time-out;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 23:26:11    Critical
      Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 23:26:01    Critical
      Ranging Request Retries exhausted;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 23:26:00    Critical
      No Ranging Response received - T3 time-out;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 23:26:00    Critical
      CM-STATUS message sent.  Event Type Code: 7; Chan ID: 2; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 23:25:49    Notice
      No Ranging Response received - T3 time-out;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 23:25:12    Critical
      Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 23:24:59    Critical
      Ranging Request Retries exhausted;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 23:24:59    Critical
      No Ranging Response received - T3 time-out;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 23:19:23    Critical
      Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 23:19:12    Critical
      Ranging Request Retries exhausted;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 23:19:12    Critical
      No Ranging Response received - T3 time-out;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 23:18:28    Critical
      Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 23:18:11    Critical
      Ranging Request Retries exhausted;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 23:18:11    Critical
      No Ranging Response received - T3 time-out;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 23:17:29    Critical
      US profile assignment change.  US Chan ID: 9; Previous Profile: 11; New Profile: 12.;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 23:17:28    Notice
      No Ranging Response received - T3 time-out;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 23:17:27    Critical
      US profile assignment change.  US Chan ID: 9; Previous Profile: 10; New Profile: 11.;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 23:17:09    Notice
      CM-STATUS message sent.  Event Type Code: 24; Chan ID: 33; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 2.;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 19:00:14    Notice
      DHCP Renew - lease parameters tftp file-^1/9A2FC592/res-600.0x30.0-D3.0 modified;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 14:12:28    Notice
      DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 14:12:28    Error
      DHCP Renew - lease parameters tftp file-^1/9A2FC592/res-600.0x30.0-D3.0 modified;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 02:59:22    Notice
      DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/15/2026 02:59:22    Error
      MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/14/2026 15:27:54    Warning
      DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/14/2026 12:11:31    Error
      DHCP Renew - lease parameters tftp file-^1/AC7C5946/res-600.0x30.0-D3.0 modified;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/14/2026 12:11:31    Notice
      CM-STATUS message sent.  Event Type Code: 5; Chan ID: 30; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/14/2026 10:57:05    Notice
      No Ranging Response received - T3 time-out;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/14/2026 01:30:01    Critical
      DHCP Renew - lease parameters tftp file-^1/1CCD80F9/res-600.0x30.0-D3.0 modified;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/14/2026 00:36:42    Notice
      DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/14/2026 00:36:42    Error
      CM-STATUS message sent.  Event Type Code: 5; Chan ID: 30; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/13/2026 17:42:18    Notice
      SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/13/2026 17:42:08    Critical
      CM-STATUS message sent.  Event Type Code: 16; Chan ID: 33; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 2.;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/13/2026 17:42:07    Notice
      SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/13/2026 17:42:06    Critical
      No Ranging Response received - T3 time-out;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/13/2026 17:42:03    Critical
      SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/13/2026 17:42:02    Critical
      CM-STATUS message sent.  Event Type Code: 16; Chan ID: 33; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 2.;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/13/2026 17:41:50    Notice
      DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/13/2026 12:29:54    Error
      DHCP Renew - lease parameters tftp file-^1/1CCD80F9/res-600.0x30.0-D3.0 modified;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:87:1a:54;CM-QOS=1.1;CM-VER=3.1;    02/13/2026 12:29:54    Notice

      S
      Wi-Fi Warriors
      Forum|alt.badge.img+42

      It looks like you’re referring to the event logs displayed on the gateway. To clarify, those event logs relate to your internet service connection rather than the gateway hardware itself. If any errors appear in the event logs, they can only be addressed and corrected by your Internet Service Provider (ISP).

      We recommend checking the cable signal levels to ensure they are within the acceptable range.

      SURFboard Community Moderator Team
      G
      The Many
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      • GWildThe Many
      • Author
      • The Many
      • February 25, 2026

      Acceptable range is +15dBm down to -15dBm, if I read the specs correctly. The issues I have are with a signal level of +8dBm, on average. Upstream is at 42dBm, another 8dB pad will cause the upstream to be near or at the limit of 50 dBm.

       

      But I get the jest of your replies. It’s up to me to figure out why my new cable modem is failing.

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