Community Forum

Re: Modem keeps losing internet connection almost daily

Highlighted
Regular Visitor

Re: Modem keeps losing internet connection almost daily

Unfortunately I don't have an answer for you, but I'm seeing the exact same drop outs with the same set of errors in the logs. They seem to come in bursts... the service will be stable for a while, then we get lots of drop outs for up to half a day or so.

 

ti_dhcp6c[8791]: 72001015-DHCPv6 Failed - No Prefix Available 
	2019/11/21 15:00:30	Critical 

ti_dhcp6c[8791]: 72001014-DHCPv6 Failed - No Address Available 
	2019/11/21 15:00:30	Critical 

ti_dhcp6c[8791]: 72001011-DHCPv6 - Missing Required Option 82 
	2019/11/21 15:00:30	Critical 

ti_dhcp6c[8791]: 72001011-DHCPv6 - Missing Required Option 82 
	2019/11/21 15:00:30	Critical 

ti_dhcp6c[8791]: 72001011-DHCPv6 - Missing Required Option 24 
	2019/11/21 15:00:30	Critical 

ti_dhcp6c[8791]: 72001011-DHCPv6 - Missing Required Option 24 
	2019/11/21 15:00:30	Critical 

ti_dhcp6c[8791]: 72001004-DHCPv6 Provision - 0 Retries Attempted with Last attempt at Thu Nov 21 20:00:29 2019 
	2019/11/21 15:00:30	Critical 

DHCPv4[8487]: 72001001-DHCPv4 Provision - Completed 
	2019/11/21 15:00:28	Informational 

DHCPv4[24160]: 72001020-DHCPv4 - IP Address Released 
	2019/11/21 14:59:07	Informational 

ti_dhcp6c[24572]: 72001011-DHCPv6 - Missing Required Option 82 
	2019/11/21 14:43:35	Critical 

ti_dhcp6c[24572]: 72001011-DHCPv6 - Missing Required Option 24 
	2019/11/21 14:43:35	Critical 

ti_dhcp6c[24572]: 72001004-DHCPv6 Provision - 0 Retries Attempted with Last attempt at Thu Nov 21 19:43:34 2019 
	2019/11/21 14:43:35	Critical 

ti_dhcp6c[24572]: 72001015-DHCPv6 Failed - No Prefix Available 
	2019/11/21 14:43:34	Critical 

ti_dhcp6c[24572]: 72001014-DHCPv6 Failed - No Address Available 
	2019/11/21 14:43:34	Critical 

ti_dhcp6c[24572]: 72001011-DHCPv6 - Missing Required Option 82 
	2019/11/21 14:43:34	Critical 

ti_dhcp6c[24572]: 72001011-DHCPv6 - Missing Required Option 24 
	2019/11/21 14:43:34	Critical 

DHCPv4[24160]: 72001001-DHCPv4 Provision - Completed 
	2019/11/21 14:43:32	Informational 

DHCPv4[6588]: 72001020-DHCPv4 - IP Address Released 
	2019/11/21 14:41:18	Informational 
Highlighted
Expert

Re: Modem keeps losing internet connection almost daily

What do the modem's signal stats look like ? Try getting them here; http://192.168.100.1

Please post the *Downstream Power Level*, the *Upstream Power Level*, and the *SNR* (Signal to Noise Ratio) numbers.

What is the exact make and model number of the modem ?

Is this a WiFi connection ?

 

Also, please post the modem component's RF error log entries (if you can access them) as those router component errors are unhelpful.



I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark the post as Best Answer!
Highlighted
Regular Visitor

Re: Modem keeps losing internet connection almost daily

Thanks for the reply. The modem is an Xfi XB6-A (I think, couldn't find another model number on the unit).

 

The upstream power levels are 5.8, 4.4, 4.4, and 4.5 with SNRs of 40.3-40.9:

 

https://imgur.com/aubfgCi

 

The downstream levels vary between 4.4 and 6 with SNRS of 40.3-40.9:

 

https://imgur.com/5RDvLqG

 

The modem only has the event log posted above, the system log, and firewall log which are both empty. I've experienced quite a few of these connection drops over the past couple of weeks and the log messages are consistent each time: always that sequence of DHCP related messages. The issues affect both wired and wireless connections. When I've had signal related issues in the past the RF messages also appeared in this log so I don't believe there are any RF related messages.

 

Also, when the connection issues occur, I've checked the Xfinity network connection status in the modem and it shows connected and locked but no IP address assigned.

 

Thanks for your help!

Highlighted
Expert

Re: Modem keeps losing internet connection almost daily

So the signal stats looked o/k at that snapshot in time, the RF error log entries would be helpful if you could get them but we've seen many posts here recently indicating that they have now blocked the end user from accessing them. A BIG mistake in my opinion......

 

Perhaps there is intermittent noise ingress into the line(s) somewhere.

 

There are other signal stat figures that can't be read by the modem. They are the "Upstream Rx Power" (Upstream Receive Power Level), the "Upstream SNR Ch." (Upstream Signal To Noise Ratio), and the "Upstream ICFR" (In Channel Frequency Response). These are as equally important in diagnosing connectivity issues as are the modem's stats.


I'm going to escalate your issue to the Comcast corporate employees that are available to these boards. They can check the CMTS (Cable Modem Termination System) for any real time degradation and / or error reports, see your node / cable plant and modem health, and see whether or not everything is in the green zone. They can also see a history plot for the modem and poll for those upstream receive signal stats.

You should get a reply here in your topic. Good luck !



I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark the post as Best Answer!
Highlighted
Official Employee

Re: Modem keeps losing internet connection almost daily

Hi, chaplovejoy. Thanks for coming here for support and for posting your modem info. We would like to look into a few other diagnostics on this end to try and get to the bottom of your connection issues. Please start by sending us a private message with your first and last name. We will continue from there.

 

To send a private message, please click our name "Comcast_Support" then select "Send a Message" on the right side.

 

Thank you. 


I am an Official Comcast Employee.
Official Employees are from multiple teams within Comcast: CARE, Product, Leadership. We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark the post as Best Answer!
Highlighted
New Poster

Re: Modem keeps losing internet connection almost daily

I have the same issue. did we get a resolution?


@chaplovejoy wrote:

Unfortunately I don't have an answer for you, but I'm seeing the exact same drop outs with the same set of errors in the logs. They seem to come in bursts... the service will be stable for a while, then we get lots of drop outs for up to half a day or so.

 

ti_dhcp6c[8791]: 72001015-DHCPv6 Failed - No Prefix Available 
	2019/11/21 15:00:30	Critical 

ti_dhcp6c[8791]: 72001014-DHCPv6 Failed - No Address Available 
	2019/11/21 15:00:30	Critical 

ti_dhcp6c[8791]: 72001011-DHCPv6 - Missing Required Option 82 
	2019/11/21 15:00:30	Critical 

ti_dhcp6c[8791]: 72001011-DHCPv6 - Missing Required Option 82 
	2019/11/21 15:00:30	Critical 

ti_dhcp6c[8791]: 72001011-DHCPv6 - Missing Required Option 24 
	2019/11/21 15:00:30	Critical 

ti_dhcp6c[8791]: 72001011-DHCPv6 - Missing Required Option 24 
	2019/11/21 15:00:30	Critical 

ti_dhcp6c[8791]: 72001004-DHCPv6 Provision - 0 Retries Attempted with Last attempt at Thu Nov 21 20:00:29 2019 
	2019/11/21 15:00:30	Critical 

DHCPv4[8487]: 72001001-DHCPv4 Provision - Completed 
	2019/11/21 15:00:28	Informational 

DHCPv4[24160]: 72001020-DHCPv4 - IP Address Released 
	2019/11/21 14:59:07	Informational 

ti_dhcp6c[24572]: 72001011-DHCPv6 - Missing Required Option 82 
	2019/11/21 14:43:35	Critical 

ti_dhcp6c[24572]: 72001011-DHCPv6 - Missing Required Option 24 
	2019/11/21 14:43:35	Critical 

ti_dhcp6c[24572]: 72001004-DHCPv6 Provision - 0 Retries Attempted with Last attempt at Thu Nov 21 19:43:34 2019 
	2019/11/21 14:43:35	Critical 

ti_dhcp6c[24572]: 72001015-DHCPv6 Failed - No Prefix Available 
	2019/11/21 14:43:34	Critical 

ti_dhcp6c[24572]: 72001014-DHCPv6 Failed - No Address Available 
	2019/11/21 14:43:34	Critical 

ti_dhcp6c[24572]: 72001011-DHCPv6 - Missing Required Option 82 
	2019/11/21 14:43:34	Critical 

ti_dhcp6c[24572]: 72001011-DHCPv6 - Missing Required Option 24 
	2019/11/21 14:43:34	Critical 

DHCPv4[24160]: 72001001-DHCPv4 Provision - Completed 
	2019/11/21 14:43:32	Informational 

DHCPv4[6588]: 72001020-DHCPv4 - IP Address Released 
	2019/11/21 14:41:18	Informational