Xfinity Technicolor Cable Modem/Router Firewall Issues


Over the last month my Xfinity router periodically goes offline. The system was working great for months and then I started experiencing periodic downtime.

Upon investigation, I noticed the following firewall log entries:

FW.IPv6 INPUT drop , 80 Attempts, 2021/6/5 07:42:47 Firewall Blocked

FW.LAN2SELF DROP , 19 Attempts, 2021/6/5 07:42:47Firewall Blocked

FW.IPv6 FORWARD drop , 11 Attempts, 2021/6/5 02:58:02

During these events, the device goes offline then will come back online eventually.

I've switched devices with Xfinity to determine if the device was the issue. Unfortunately, the new device has the same issue.

So far, I've disabled the integrated firewall, disabled upnp, and turned off IPv6 on all my PCs. Same issue still occurs.

My configuration is the following:

XFINITY Router/Modem --> VPN Appliance --> Google Mesh Router

I've also enabled bridge mode on the XFINITY device. Same issues occur.

I've been using the same hardware, cables, connectors, etc. for months prior before this started happening. Essentially, nothing was changed.

There are several support entries at Xfinity on this issue, but very little around resolutions.

Any input will greatly be appreciated!



Best Answer

  • Puttygutt
    Puttygutt Member Posts: 3
    First Comment Photogenic
    #2 Answer ✓

    Xfinity tech came out and determined the service line (outside coax to the pedestal) had significant noise. The tech replaced the service line, installed new Moca ground filter outside and new line from filter to inside. I only have three cable boxes and one internet connection. The original install had a commscope amplifier. The tech recommended not using the amplifier since I only had four devices. He replaced the amplifier with a splitter. According to the Tech, the commscope amps are only needed if you have several cable boxes and will only amplify problems if there is a line issue causing a ton of noise on the system. The Tech also replaced all the coax connectors at each end of the line, including the lines in the walls and the lines connecting the wall plates to the devices. Everything is running significantly better. So far, no internet drops and the cable channels are working much better. We had some Pixelation on some HD channels and those are all resolved.

    In summary, the main service line was suspect. It's been in place for 20+ years. The tech knew early in the discussion that there was a line problem. Also, having a Tech who cares makes a huge difference. He was a Rockstar and was laser focused on solving our issues.



  • Pixel
    Pixel Devon, U.K.Member, Moderator, Beta Tester Posts: 358
    100 Likes 25 Answers 100 Comments 25 Agrees
    Have you tried disabling IPV6 on your Router/Modem?
    I think that if other people are having the same problem you would be better off “speaking” to the hardware supplier/manufacturer.
  • Puttygutt
    Puttygutt Member Posts: 3
    First Comment Photogenic
    Thanks for the feedback.  I've disabled IPv6 across the board (routers, workstations, etc.).  However, I believe the issue is happening outside the home. Yesterday, Comcast/Xfinity posted that maintenance will occur tonight in our area.  I hope this will solve the intermittent outages we've been experiencing.  I will report back once I test post maintenance.