Solved DNS changing repeatedly at the same time every evening

[dingo123]

For several months I have had an issue where the internet drops at just about the same time each evening. During the day there is no problem. It affects all devices. The troubleshooting error on my PC shows DNS problems. I have checked the modem and it appears that the DNS is automatically changing repeatedly (every few minutes). I have tried changing the DNS servers first to Open DNS and afterwards to Google DNS but the problem persists. I have tried switching off the modem and back on again but no effect. I have not yet reset to factory settings but I assume something external is affecting the DNS changes (I am with Vodafone home internet and the DNS server changes all point to Vodafone servers).

I have done virus / malware scans on my PC.

Any ideas? Many thanks.

 

[KKLC]

when the DNS issue happen at night, did you try to ping 8.8.8.8 and ping google.com? Please try them if you havent yet, and post what your results are.

 

[dingo123]

Thank you. I just tried it.

It says "request timed out"

 

[KKLC]

Thank you. I just tried it.

It says "request timed out"

it says time out even when you pinged 8.8.8.8 ? it doesn't seem to be the DNS, but your network issue, probably your modem or router.

how long does it take to recover after the connection drop?

 

[TerryNet]

Separate modem and router or a combination unit?

When internet access is lost you can still communicate with the router? With the modem (if separate)?

 

[dingo123]

Yes, I mentioned that it appeared to be a modem/router issue. The DNS changes on the modem settings. Yes I can communicate with the modem. I can login and change settings. The modem DNS changes itself - whilst changing it reverts to 0.0.0.0. Takes about 2 minutes to recover - like the time it takes to reset / reboot. Thank you.

 

[TerryNet]

Could be maintenance time for the ISP. Have you discussed the issue with the ISP?

 

[dingo123]

Thank you. I doubt it is maintenance as it has been happening for 2-3 months. But, yes, I think you are right. I was hoping I could somehow fix from my end because there is a language barrier at my end but everything appears to point to ISP.

Thank you all very much for your kind help.

 

[Couriant]

Have you done a factory reset of the device to see if that helps?

If the modem is losing its Internet (WAN) information then it would be one of three things: 1) Bad modem, 2) bad connection, or 3) bad service. Eliminate 1 and 2 before blaming 3.

 

[dingo123]

Thank you very much. I will do what you advise.

 

[TerryNet]

You've marked it 'Solved.' What was the solution?

 

[dingo123]

Well, looks like I made a mistake. I marked it solved so that nobody would continue to take trouble to give further advice whilst I was awaiting further action. Sorry. Been away a few days but now back and will try the advice I was given. Thanks.

 

[plodr]

the DNS is automatically changing repeatedly (every few minutes).

That is not normal behavior.
If it continues to happen, you need a new modem.

 

[dingo123]

Thank you. Tonight I will be resetting my modem and will then sort the problem with my ISP if it continues. Thanks.

 

[dingo123]

After a long wait - partly compounded by my travels - the problem is sorted. It turns out that it was something to do with the connection outside of my control. Some guys checked the local box and went back to the telephone exchange office (whatever it is called) and did something. The connection works better now - the speed is a paltry 3.5 but that is not atypical for where I am. The problem was "fixed" yesterday at lunchtime but last evening the modem kept resetting itself all evening. I phoned to log a new issue (ASDL light kept flickering and turning off - I had already checked connections in the home, rebooted the modem and reset it to factory settings). They logged another ticket for the crew to sort but this morning the modem is working and the speed is 6. Could be a temporary issue.

Thank you to everyone who tried to help. It is greatly appreciated.