Monday night (4/13/20), our Motorola MB7621 modem rebooted for reasons I can't explain. It knocked our Google WiFi system off-line as well, of course. Over the last 2 days, I have spent countless hours trying to get our Google Wi-Fi reconnected with no success.
When I connected my laptop to the modem directly via ethernet, I see that the modem has an IPv6 address but no entry under "IP ADDRESS" - it says none. There is no IPv4 address being reported in the modem. When I look at the modem event log, it says that "No Ranging Reponse Received - T-3 timeout". I was finally able to get a Comcast tech to come out and he replaced a connector on the side of the house and a tap at the street but said that the levels in the plant look good. When I asked about the T-3 and T-4 issues, he said that it was due to "electricity finding its way into my modem from one of my other devices" since he ran a FVD over the modem and it registered a 12volt leakage. He had no answer on the lack of an IP address.
I have talked with Motorola Tech support twice and they say that the modem UI clearly shows no IPv4 address and that it is caused by faulty or incomplete provisioning by Comcast, that I need to request Comcast to address the provisioning and "push an IPv4 address to the modem". I have also spoken with Google tech support twice and they said that while the Google WiFi system will support IPv6 addressing, the connection between the Google WiFi hub and the modem must first be established using IPv4. I have had our Google WiFi and Moto 7621 modem operating for the last year without issue and when I installed it initially, it came up very easily so I know that at that point, the modem was providing an IPv4 address to the Google WiFi hub. When I attempt the connection now, I get "Connection Error" from the Google WiFi UI.
I have made countless attempts to reboot the modem, call Comcast and spend hours on the phone with them, and generally chase my tail to have now gotten nowhere in over 48 hours. I was talking with a friend this morning, and he mentioned that it is possible that Comcast was running out of IPv4 addresses with such an increase in network traffic and devices during this COVID19 event and that they may have had to move to all IPv6 for home services. I now suspect that Comcast may have made just such a change in their provisioining recently (since the modem UI says "IPv6 address" and one of the Comcast tech support persons said that they use IPv6 provisioning) and that following the unexplained reboot Monday night, the modem came back up with only an IPv6 address and this is now why I can't get the Google WiFi reconnected. My only solutions now appear to be either 1) begin leasing and XB6 and extenders from Comcast, or 2) try to find a WiFi mesh system that supports IPv6-only addressing.
Thoughts? Below are the current US/DS stats:
|Channel||Lock Status||Modulation||Channel ID||Freq. (MHz)||Pwr (dBmV)||SNR (dB)||Corrected||Uncorrected|
|Channel||Lock Status||Channel Type||Channel ID||Symb. Rate (Ksym/sec)||Freq. (MHz)||Pwr (dBmV)|
|Time Not Established||Critical (3)||No Ranging Response received - T3 time-out;CM-MAC=00:40:36:56:ac:85;CMTS-MAC=00:01:5c:b2:70:48;CM-QOS=1.0;CM-VER=3.0;|
|Time Not Established||Notice (6)||Honoring MDD; IP provisioning mode = IPv6|
Hi there. Thanks for posting. Have you noticed any additional changes or progress on this, since you created this post?
After many, many hours on the phone with Comcast, Motorola, and Google, during my 3rd call to Motorola, the Motorola tech said something that no one else had hit upon. He suggested that I disconnect everything from the modem and perform another hard reset, and then connect just the coax, and then connect Google WiFi - do not connect my laptop to the modem to check the status and then disconnect the laptop and connect the Google WiFi. Apparently, the Motorola modem remembers the first IP address it sees following a factory reset.
Understood. Things can get a little fuzzy when it involves 3rd party equipment or services. I am glad you were able to find the missing piece to the puzzle. Thank you for posting what you found out here. It may help someone else down the road.