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"Ethernet" doesn't have a valid IP configuration

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"Ethernet" doesn't have a valid IP configuration

Problem: intermittent no internet connectivity
Running network troubleshooter gives me the error message: "Ethernet" doesn't have a valid IP configuration

My system
Toshiba satellite laptop S75 hardwire to a personal modem arris sb6141, my ISP is Comcast xfinity. No router. I have high speed internet.

I have had the same setup for at least 2 years without this problem. All of the sudden about a month ago, I started getting no internet connection intermittently
Without any updates or changes to my system. The issue comes and goes, meaning sometimes there is no internet in the morning, I will come home from work at night and internet will be working.

I have talked to Comcast reps over the phone many times and they tell me it looks good on their end and that they can see my modem, they did a reset of my modem but it didn't help.
Comcast has sent 2 different techs at my place and they both said the wiring has no issue.
I have replaced the Ethernet cable, but there is no improvement.
When it first started I had windows 10 pro original version on my laptop, I updated windows 10 to build 1803 but it didn't help.
Then I updated windows 10 to build 1809 and internet started working again for a week with no issue at all.
Then the intermittent no connectivity issue came back.
The lights on the modem look good. There is no yellow exclamation point in the device manager. The IP configuration is set to obtain an address automatically. I have done a network reset. I need your help, please.
I can get wi-fi to work on same laptop (open xfinity wi-fi from neighbor).

 

I installed the latest drivers, the network driver version is now 10.31.828.2018 and I did a network reset, but it didn't help. Ethernet is working right now a s I type.

Expert

Re: "Ethernet" doesn't have a valid IP configuration

Start here;

 

https://forums.xfinity.com/t5/Your-Home-Network/Connection-Troubleshooting-Tips/m-p/1253575#M94474

 

Post the requested info from here;

 

https://forums.xfinity.com/t5/Your-Home-Network/Information-Requested-for-Connection-Related-Posts/m...

 



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Frequent Visitor

Re: "Ethernet" doesn't have a valid IP configuration

Retail SURFboard Cable Modem

ARRIS SB6141 | Model number: SB6141    

No router.

I contacted Comcast numerous times and had 2 tech visits, they found no issue with the wiring.

The lights on the modem look the same whether ethernet is working or not.

Ethernet is working as I type.

 

screenshot of my upstream and downstream signal levels and screenshot of my modem’s error logs

 

https://image.frl/7w795

https://image.frl/gaebq

 

Screenshot_2019-01-14 Screenshot(1).png

 

 

Screenshot_2019-01-14 Screenshot.png

Expert

Re: "Ethernet" doesn't have a valid IP configuration

Can't see your pics. Since you are a new poster, they likely need to be approved by a Forum Admin. Or you may need to make a minimum number of posts.

You could try hosting them at one of those free third-party pic hosting sites and post the link to them here.



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Frequent Visitor

Re: "Ethernet" doesn't have a valid IP configuration

done

Expert

Re: "Ethernet" doesn't have a valid IP configuration

The upstream power is approaching the high side and may be intermittently fluctuating even higher to out of spec levels. That can cause random disconnects, spontaneous re-booting of the modem, and speed and latency problems.

In a self troubleshooting effort to try to obtain better connectivity / more wiggle room, check to see if there are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage types like GE, RadioShack, RCA, Philips, Leviton, Magnavox, and Rocketfish from big box stores like Home Depot, Lowes, Target, Wal-Mart etc. Splitters should be swapped with known to be good / new ones to test

If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two way splitter connected directly off of the drop from the street/pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed, and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.




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Re: "Ethernet" doesn't have a valid IP configuration

There is no splitter. It's a single coaxial cable from the wall to the modem. 2 comcast techs already came to my appartment and said the wiring was fine. Ethernet is working right now.

Expert

Re: "Ethernet" doesn't have a valid IP configuration

The power levels don't lie. Get the techs involved again until it is fixed right !

 

That elevated upstream power shows that there is some type of return path impairment. Bear in mind that if the premises facing techs can not find or fix a problem at your home, it is they who are responsible for escalating it to their line / network / maintenance dept. techs. The problem may lie beyond your home in the local neighborhood infrastructure somewhere. Good luck !

 

 



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Frequent Visitor

Re: "Ethernet" doesn't have a valid IP configuration

Following your advice I had a comcast tech come to my appartment this morning and I requested that he replaced a splitter I noticed outside my apartment. He removed the splitter. Internet was working when he got here and is still working as I type. I will monitor the internet in the next few days and will post back if there are any more issues. You were right that removing or replacing the splitter would have an impact on the upstream power. It seems to be within specs now whereas it was almost out of specs before. Below is a screenshot of my updated upstream and downstream signal levels.

 

https://img.frl/ytsre

Screenshot_2019-01-18 Screenshot.png

Highlighted
Expert

Re: "Ethernet" doesn't have a valid IP configuration

Looking better !



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Frequent Visitor

Re: "Ethernet" doesn't have a valid IP configuration

The problem reappeared. Any other suggestions?

Expert

Re: "Ethernet" doesn't have a valid IP configuration

Get the techs involved again until it is fixed properly. 

 

Bear in mind that if the premises facing techs can not find or fix a problem at your home, it is they who are responsible for escalating it to their line / network / maintenance dept. techs. The problem may lie beyond your home in the local neighborhood infrastructure somewhere. Good luck !



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Official Employee

Re: "Ethernet" doesn't have a valid IP configuration

Hi @totototo10

 

Sorry for the experience you're having. @EG is correct. We will need to get another tech out who can refer this to your local line/maintenance team for further investigation. If you don't mind, I'd like to access your account so I can gather more details about your premise signal levels, and check the health of the node to see if I'm able to isolate a cause, as well as pass any relevant information to the Field Tech, who can use that information on the referral to the line/maintenance crew. 

 

In order to assist you, please send me a private message verifying your first and last name, as well as the name of the account holder if it's different than yours.  

 

To send a private message click on my name "ComcastChe", then click send a message. 

 


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Frequent Visitor

Re: "Ethernet" doesn't have a valid IP configuration

Does anyone knows what causes a short lease? My ethernet is working right now but didn't work at all yesterday. I have been monitoring some network details by doing ipconfig /all.

When ethernet works, I get a valid ip and an ip lease that says it would expire in 3~4 days.

When ethernet doesn't work the ip address is 169.254.xxx.xx (where xx are hidden numbers). What cause the DHCP not to acquire a valid ip address from the ISP?

Expert

Re: "Ethernet" doesn't have a valid IP configuration


@totototo10 wrote:

Does anyone knows what causes a short lease?

 

It's not a "short lease" if it is set for 3-4 days. That is typical and can't change. Something is malfunctioning if it is lost before that. The IP lease itself is not expiring.

 

My ethernet is working right now but didn't work at all yesterday. I have been monitoring some network details by doing ipconfig /all.

When ethernet works, I get a valid ip and an ip lease that says it would expire in 3~4 days.

When ethernet doesn't work the ip address is 169.254.xxx.xx (where xx are hidden numbers). What cause the DHCP not to acquire a valid ip address from the ISP?

 

If you is are connected to a router / gateway device, when you perform an ipconfig /all, the lease time that you are seeing on the LAN is being issued by the router's built in DHCP server, not the ISP's DHCP server.

 

A 169.254.xxx IP address is self assigned by the computer's operating system when a valid DHCP IP address lease can not be obtained for whatever the reason may be.


 



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Frequent Visitor

Re: "Ethernet" doesn't have a valid IP configuration

Thank you all for your responses. I bought and set up a router and both wi-fi and ethernet (from my laptop to the router) seem to be working so far.

Official Employee

Re: "Ethernet" doesn't have a valid IP configuration

Happy to hear that helped. Let us know if you need anything in the future. 


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