Random DNS issues on Windows 10 machine

Since yesterday evening I've noticed multiple issues with sites randomly not being found, in Chome, Edge (Chrome version), and Firefox, only on my Windows 10 machine. My phone is fine, as are other devices in the house.

I've been using 8.8.8.8 and 8.8.4.4 on my machine, but also tried 1.1.1.1 which I've used before, and a mix of those, or just one set of DNS IP addresses at once in case one service was causing issues.

What I am noticing is that randomly when this happens I'm getting timeouts on the pinging of the addresses I'm trying to visit, and some cases I'm getting a different response, such as pinging www.amazon.co.uk sometimes comes back as www.amazon.co.uk and other times 'dmv2chczz9u6u.cloudfront.net' despite changing nothing at all.

I'm on PlusNet, my router is set to 8.8.8.8 and 8.8.4.4, but on my machine I'm specifying the DNS servers for that specific machine. winver is 1909 build 18363.900

Some examples of ping attempts:

Microsoft Windows [Version 10.0.18363.900]
(c) 2019 Microsoft Corporation. All rights reserved.

C:\Users\Simon>ping www.amazon.co.uk
Ping request could not find host www.amazon.co.uk. Please check the name and try again.

C:\Users\Simon>ping www.amazon.co.uk

Pinging e15314.e22.akamaiedge.net [23.44.101.46] with 32 bytes of data:
Reply from 23.44.101.46: bytes=32 time=11ms TTL=57
Reply from 23.44.101.46: bytes=32 time=11ms TTL=57
Reply from 23.44.101.46: bytes=32 time=11ms TTL=57
Reply from 23.44.101.46: bytes=32 time=11ms TTL=57

Ping statistics for 23.44.101.46:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 11ms, Maximum = 11ms, Average = 11ms

C:\Users\Simon>ping payment.tesco.com

Pinging e17021.x.akamaiedge.net [23.198.66.98] with 32 bytes of data:
Reply from 23.198.66.98: bytes=32 time=11ms TTL=57
Reply from 23.198.66.98: bytes=32 time=11ms TTL=57
Reply from 23.198.66.98: bytes=32 time=11ms TTL=57
Reply from 23.198.66.98: bytes=32 time=10ms TTL=57

Ping statistics for 23.198.66.98:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 10ms, Maximum = 11ms, Average = 10ms

C:\Users\Simon>ping www.tesco.com

Pinging e2008.x.akamaiedge.net [23.214.182.193] with 32 bytes of data:
Reply from 23.214.182.193: bytes=32 time=11ms TTL=56
Reply from 23.214.182.193: bytes=32 time=12ms TTL=56
Reply from 23.214.182.193: bytes=32 time=11ms TTL=56
Reply from 23.214.182.193: bytes=32 time=10ms TTL=56

Ping statistics for 23.214.182.193:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 10ms, Maximum = 12ms, Average = 11ms

C:\Users\Simon>ping payment.tesco.com

Pinging e17021.x.akamaiedge.net [23.214.166.22] with 32 bytes of data:
Reply from 23.214.166.22: bytes=32 time=11ms TTL=55
Reply from 23.214.166.22: bytes=32 time=13ms TTL=55
Reply from 23.214.166.22: bytes=32 time=11ms TTL=55
Reply from 23.214.166.22: bytes=32 time=12ms TTL=55

Ping statistics for 23.214.166.22:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 11ms, Maximum = 13ms, Average = 11ms

C:\Users\Simon>ping google.com

Pinging google.com [74.125.133.101] with 32 bytes of data:
Reply from 74.125.133.101: bytes=32 time=18ms TTL=106
Reply from 74.125.133.101: bytes=32 time=18ms TTL=106
Reply from 74.125.133.101: bytes=32 time=17ms TTL=106
Request timed out.

Ping statistics for 74.125.133.101:
Packets: Sent = 4, Received = 3, Lost = 1 (25% loss),
Approximate round trip times in milli-seconds:
Minimum = 17ms, Maximum = 18ms, Average = 17ms

C:\Users\Simon>ping www.tesco.com
Ping request could not find host www.tesco.com. Please check the name and try again.

C:\Users\Simon>ping www.tesco.com

Pinging e2008.x.akamaiedge.net [23.214.182.193] with 32 bytes of data:
Reply from 23.214.182.193: bytes=32 time=11ms TTL=56
Reply from 23.214.182.193: bytes=32 time=10ms TTL=56
Reply from 23.214.182.193: bytes=32 time=58ms TTL=56
Reply from 23.214.182.193: bytes=32 time=11ms TTL=56

Ping statistics for 23.214.182.193:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 10ms, Maximum = 58ms, Average = 22ms

C:\Users\Simon>ping amazon.co.uk

Pinging amazon.co.uk [54.239.34.171] with 32 bytes of data:
Reply from 54.239.34.171: bytes=32 time=22ms TTL=224
Reply from 54.239.34.171: bytes=32 time=22ms TTL=224
Reply from 54.239.34.171: bytes=32 time=49ms TTL=224
Reply from 54.239.34.171: bytes=32 time=20ms TTL=224

Ping statistics for 54.239.34.171:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 20ms, Maximum = 49ms, Average = 28ms

C:\Users\Simon>ping amazon.co.uk

Pinging amazon.co.uk [54.239.34.171] with 32 bytes of data:
Reply from 54.239.34.171: bytes=32 time=20ms TTL=224
Reply from 54.239.34.171: bytes=32 time=21ms TTL=224
Reply from 54.239.34.171: bytes=32 time=21ms TTL=224
Reply from 54.239.34.171: bytes=32 time=21ms TTL=224

Ping statistics for 54.239.34.171:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 20ms, Maximum = 21ms, Average = 20ms

C:\Users\Simon>ping www.amazon.co.uk

Pinging dmv2chczz9u6u.cloudfront.net [13.35.243.34] with 32 bytes of data:
Reply from 13.35.243.34: bytes=32 time=11ms TTL=245
Reply from 13.35.243.34: bytes=32 time=12ms TTL=245
Reply from 13.35.243.34: bytes=32 time=13ms TTL=245
Reply from 13.35.243.34: bytes=32 time=18ms TTL=245

Ping statistics for 13.35.243.34:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 11ms, Maximum = 18ms, Average = 13ms

My connection isn't dropping when this happens, I've still got video streams working fine on the same PC, and it's not just a buffer that is built up on the stream, and also streams/connectivity on other devices. TBB speed test seems to suggest the up/down speeds are normal, but I think that's just to confirm that it's the DNS (or my machine?) rather than my connection itself causing these issues. I've also rebooted my PC and gone through all the typical checks, but I'm now at a loss.

Any ideas what may be wrong?

I get a couple of errors in Chrome, this is the one most often:

No Internet
Try:

Checking the network cables, modem and router
Reconnecting to Wi-Fi
DNS_PROBE_FINISHED_NO_INTERNET

But despite that "no internet", there is.


That latest error happened whilst browsing thinkbroadband.com, and ping attempts a few seconds apart each:

C:\Users\Simon>ping thinkbroadband.com
Ping request could not find host thinkbroadband.com. Please check the name and try again.

C:\Users\Simon>ping thinkbroadband.com
Ping request could not find host thinkbroadband.com. Please check the name and try again.

C:\Users\Simon>ping thinkbroadband.com
Ping request could not find host thinkbroadband.com. Please check the name and try again.

C:\Users\Simon>ping thinkbroadband.com
Ping request could not find host thinkbroadband.com. Please check the name and try again.

C:\Users\Simon>ping thinkbroadband.com

Pinging thinkbroadband.com [80.249.106.141] with 32 bytes of data:
Reply from 80.249.106.141: bytes=32 time=11ms TTL=57
Reply from 80.249.106.141: bytes=32 time=10ms TTL=57
Reply from 80.249.106.141: bytes=32 time=10ms TTL=57
Reply from 80.249.106.141: bytes=32 time=11ms TTL=57

Ping statistics for 80.249.106.141:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 10ms, Maximum = 11ms, Average = 10ms

Surely if you've got a custom DNS setup at router level then there's no need to have the same DNS setup at PC/client level as well?

Have you got any security software installed or any nonsense like that?

Can you post an ipconfig /all for our sanity?

Let's use the right tool for the job, you are troubleshooting DNS, you'll need nslookup to assist the diagnosis.

nslookup <fully qualified domain name> <lookup server>

For example nslookup www.tesco.com 1.1.1.1 will use Cloudflare to resolve www.tesco.com.
This should assist in narrowing down if one of your DNS servers is misbehaving. When it comes to free DNS you get what you pay for and your own ISP may well be more effective. Don't forget, once a look up has been completed Windows will cache the result for a period of time to avoid having to do all that work again.

Be aware that Chrome, Firefox and others may have DNS-over-HTTPS (DoH) enabled. This is where the browser handles DNS itself, and doesn't ask the operating system.

Also on Windows you can issue ipconfig /flushdns to clear Windows local memory of lookups, so it will ask again.

If you are setting DNS on the router, and using DHCP for the PC, then why bother changing DNS on the PC. Also the router may cache DNS lookups.

And the best tool for querying DNS is the command dig - but this doesn't come built in to Windows, but if you have a Linux machine (or even a Mac) it is more comprehensive than nslookup.

There is a Windows version, but its a pain to install:
https://www.configserverfirewall.com/windows-10/dig-...

Thank you for all the help. I'm pleased to say that without doing anything, it all "cleared up" late yesterday evening, and around 24 hours later I've not had the issue once since, and that's without making any changes at all.

Slightly strangely, and I think a coincidence, but when speaking with a family member in another town and on another ISP, they had been having the same sort of issues during the day too. But I've not seen widespread reports of it anywhere else, so I can't think it's a general issue. Very odd.

To answer the question about security software, nothing, no parental controls, just using the built-in Windows Defender in Windows 10. Anyway, it seems "fixed" now, like all the best tech problems where it just goes away and then makes it fairly impossible to keep trying to work out what was wrong in the first place...

how old is the pc?if it has recently updated to win 10 build 2004 and it has what microsoft class as "incompatible drivers"(old ones that can't be updated to compatible ones)on any piece of hardware you will be having problems similar to those described:-try going into
settings/windows security/device security/core isolation and turning off memory integrity
I have had to do this due to drivers on graphics card not being compatible with this and were causing all kinds of issues, funnily enough not graphics issues, its not an ideal solution turning off some of the security apparently Microsoft are aware of this issue and it is workaround they recommend

Edited by steve195527 (Tue 16-Jun-20 10:58:51)