mb8611 firmware

Piling on here, I have the same issue with the same modem.  This modem has been supported by comcast for a long time and up until recently worked great.  I have posted in the forums here and direct messaged the xfinity support team via the provided method.  I have received no response nor acknowledgement of my issue.  Apparently xfinity feels they bear no responsibility despite the fact that they are the ones creating the issue.  Really disgusted by the poor level of customer support here and lack of ownership of this technical issue.  

Here's another MB8611 user experiencing reboots nearly twice an hour for the last 6 hours. This is completely unacceptable.

I'm working from home. If it's this bad tomorrow I don't know how I'm going to get any work done

I capture BM8611 modem stats and sent it to Motorola support, they reply:
"Thank you for providing that information. Looking at this there seems to be something wrong with your coaxial cable coming into the device. Your corrected/uncorrected numbers in the downstream bonded channels box should be at 0. Those are all errors coming into the device through that line. I would have your service provider come out and check those lines. As soon as they do, and fix that problem, you will be able to use your service without interruptions."

This issue (freeze and reboot) starts early January, I use modem one month before with no one reboot. Just analyze what you change in firmware and roll it back. You may make update or setup old firmware version for our modems that work fine with your network communication equipment. 

Just take old firmware from Motorola and send update to our modems, as you do with current unstable version.

P/S my modem reboots 20+ times today. You must do something. 

@user_4bffe4 

Your post with that first pic of the Device Information was marked as being "Private" by the forum software because it contains CM MAC and the CMTS MAC addresses. They are considered to be personal information. The posting of personally identifiable information is a violation of their forum guidelines. Please delete that pic only. Thank you.

Any updates on a fix? I have been having these issues since December! And just found this issue is related to the 21.3.7 firmware. Has comcast mentioned a fix yet?

This is frustrating, this is what Comcast advises 

“I can check the Xfinity internet connectivity for you. If it’s a modem issue you need to contact modem manufacturer to check modem.”

Ashish

As with everyone else, I have no problems with firmware version  8611-19.2.18 , It is only once comcast pushes through 8611-21.3.7 do I constantly lose internet

I know this post has gotten old, but I thought I'd mention something I noticed about two weeks ago. Quick recap: I have a new Xfinity install as of December 2022 and have a Motorola MB8611 modem + my own router. When I got the modem, it had firmware version 8611-19.2.18. A few weeks later, it was upgraded to 8611-21.3.7. However, unlike most people posting here, I had no problems with the Internet dropping out on either version. 

Two weeks ago, I noticed that the blue downstream arrow on the modem was blinking, which means the modem is "Negotiating bonded channel(s)," according to the MB8611 Quick Start Guide. This has happened a few times, and rebooting the modem fixes it for quite a while. I logged into the modem to reboot it and found that the firmware version had been downgraded to 8611-19.2.18 on February 17th. I wanted to give it a few days to see if it "stuck" or got upgraded back to 8611-21.3.7. It's been two weeks, and the firmware version has stayed at 8611-19.2.18. I am guessing that Xfinity's temporary fix is to downgrade all MB8611s to the older firmware until Motorola creates a new version (hopefully without the disconnection issues).

Side note: the MB8611 Quick Start Guide has a footnote for the blinking downstream light saying: "If a blue Upstream or Downstream light blinks continuously, this indicates partial service (at least one designated channel has not completed bonding). You should still get high Internet speeds, but your service provider may want to know so they can adjust their network."

I also posted this on this thread: https://forums.xfinity.com/conversations/your-home-network/motorola-mb8611-modem-keeps-restarting-firmware-issue/63bb6c5b507b4d3af9e1b39e?page=3 

I guess I am a bit late to the sad party, but I am having the same issues. I've been having these issues consistently for the last 6 months, maybe longer tbh, but I don't remember when they first started. 

Here is what I've done so far, but again, the problem still persists.

1. Had Comcast run a new line from the pole into my house (to be fair the line was probably 10-15 years old)
2. Had Comcast replacee a peice of hardware on the line, where my cable line plugged into
3. RMAed my modem with Motorola and replaced it 2 weeks ago (took a little back and forth with them but not a long time)

Today, I spent 1.5 hours with the most technical Comcast Tech I've worked with so far and basically he found nothing. He checked pretty much everything, and showed me everything he was checking. We compared all that he was checking with my "Connection" info (from the Motorola Admin screen) and everything seemed great. 

I never thought to check the version number of the modem's software, but I am currently on 19.2.18 (I hard reset my modem today tho)

I hard reset my modem today, so unsure if this was the a different version before this and I don't know what version I was on with my older peice of hardware. Either way, this is really disappointing becuase Comcast should not recommend this hardware (obviously this is an issue) and Motorola should not sell it (or both Companies should ideally fix it, but that doesn't seem like it's going to happen). 

My next steps are to try another non-Motorola modem - either by renting or buying a new one and trying to return it before the 30 day mark (or sell the Motorola one online). 

If anyone has any questions, happy to answer. 

So if I am having this issue, how can I get the 21.3.7 firmware update?  I’m about to switch to T-Mobile internet since I need a reliable connection but I am willing to try one more thing. I have been dealing with this for over a year and have had 4 technicians come out and only noticed this today when the technician told me to update my firmware