I have new Modem for about a month. I registered modem with Xfinity successfully. I use a Google Wifi Router. I inconsistently have connection issues. DownStream is tyically blinking. Firmware is V3.02.01attached is my event log - upstream shows Unlocked. I've had a Xfinity tech come out and said it was a port issue on outside of home. Worked ok for about 5 days. Today it is crashing every 10-15 mintues. Xfinity tech is coming out again this weekend Please give any guidance.

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. Be sure to power OFF the modem for 1 minute them back ON.https://community.netgear.com/t5/Cable-Modems-Routers/General-info-and-Troubleshooting-for-Cable-Modems/m-p/1530376#M12853

Xfinity tech came out and replaced ALL coax to my apartment. he did spot some shielding damage in some spots. However, still blinking downstream light. We did a hard reset on modem and hardwired directly to laptop. Still blinking downstream light. Here is recent Event log

Were all the Downstream channels locked in? I see 31 is locked in. What speed do you pay for UP and DOWN? Your only getting 1 channel on the UP BONDED locked in, there should be 4 I believeIs LAG enabled on the modem? Link Aggregation The ISP should look into this with you. Have them review the signal up to the modem and the event and cable connection logs.

i pay for Blast which is 200mps I cannot find where LAG shows on Netgear page. i attached more info from Admin Netgear Modem page

DisableEnable (LACP-IEEE 802.3ad) (Port 1 & 2)Ethernet Port Aggregation Status: Inactive

CM1200 and Xfinity connection issues

20 Replies

FURRYe38
Guru - Experienced User
Mar 19, 2021
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.
Be sure to power OFF the modem for 1 minute them back ON.
https://community.netgear.com/t5/Cable-Modems-Routers/General-info-and-Troubleshooting-for-Cable-Modems/m-p/1530376#M12853
- Julia37
  Aspirant
  Mar 21, 2021
  Xfinity tech came out and replaced ALL coax to my apartment. he did spot some shielding damage in some spots.
  However, still blinking downstream light.
  We did a hard reset on modem and hardwired directly to laptop. Still blinking downstream light. Here is recent Event log
  NETGEAR Modem CM1200 march 21.pdf229 KB
  - FURRYe38
    Guru - Experienced User
    Mar 21, 2021
    Were all the Downstream channels locked in? I see 31 is locked in.
    What speed do you pay for UP and DOWN?
    
    Your only getting 1 channel on the UP BONDED locked in, there should be 4 I believe
    Is LAG enabled on the modem? Link Aggregation
    
    The ISP should look into this with you. Have them review the signal up to the modem and the event and cable connection logs.

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CM1200 and Xfinity connection issues