Check the Mac Address of the ethernet Adapter to see if it has changed to nothing. 

When it works put 'ipconfig /all' in an admin command prompt to see.

DO NOT POST THAT INFORMATION HERE.

Typically this kind of problem is associated with winsock rootkit malware and cannot be fixed without wiping the drive.

You could try fresh start with admin command prompt

systemreset -cleanpc

YES because it should never be zeros.

You can disable IP6 and ISATAP and Teredo to help fix this as the malware is using IP6.

the first boarn identity will have lots of Krap

The second boarn identity will have almost nothing.

rem **************************

DO not post Mac Addresses or IP addresses here.

Run the following in Admin Command prompt

netstat -b -o -a -r -n

netsh interface teredo set state disabled
netsh interface teredo show state
netsh interface ipv6 isatap set state state=disabled
netsh interface ipv6 isatap show state
netsh interface ipv6 6to4 set state state=disabled undoonstop=disabled
netsh int ipv6 6to4 show state

netstat -b -o -a -r -n

rem*********************************

The addresses below are RFC 1918 so they are ok to post.  127.0.0.1 IS LOOPBACK

169.254.XXX.XXX IS DEAD DHCP SERVER

https://datatracker.ietf.org/doc/html/rfc1918

IPv4 Route Table
============================
Active Routes:
Network Destination Netmask Gateway Interface Metric
0.0.0.0 0.0.0.0 10.0.0.1 10.0.0.129 35
10.0.0.0 255.255.255.0 On-link 10.0.0.129 291
10.0.0.129 255.255.255.255 On-link 10.0.0.129 291
10.0.0.255 255.255.255.255 On-link 10.0.0.129 291
127.0.0.0 255.0.0.0 On-link 127.0.0.1 331
127.0.0.1 255.255.255.255 On-link 127.0.0.1 331
127.255.255.255 255.255.255.255 On-link 127.0.0.1 331
224.0.0.0 240.0.0.0 On-link 127.0.0.1 331
224.0.0.0 240.0.0.0 On-link 10.0.0.129 291
255.255.255.255 255.255.255.255 On-link 127.0.0.1 331
255.255.255.255 255.255.255.255 On-link 10.0.0.129 291
=====================
None

IPv6 Route Table
========================
Active Routes:
If Metric Network Destination Gateway
1 331 ::1/128 On-link
1 331 ff00::/8 On-link
========================================
Persistent Routes:
None

hi @speedstep , I ran the command and got a good Physical Address for the Ethernet Adapter and a lot of zeroes for the Teredo Tunneling Adapter, does this confirm your theory?

Seeing something similar on my XPS 15 (9560).  Running Windows 10 Pro w/ 21H1, OS Build 19043.1151, and no firewall or AV protection other than what's built into Windows.  

After installing KB5005033, my internet connection icon stayed connected/up but connections to various internet assets would fail to load, seemingly randomly.  Broken images, connection resets, and portions or all parts of web pages would not load.  

I tried a couple of different browsers, including Chrome (latest version) and Firefox, but the same problem existed.  I also tried the Postman app outside of the browser and it failed frequently as well.  Failures weren't continuous but were frequent enough that I couldn't work normally.  The only error messages that would appear in console logs were ENOBUFS in Postman and 0x80070008 in Chrome.

My connection is ethernet based but I also tried wifi.  Same problem on both.  Other computers and devices on the same network didn't exhibit the problem.  Tried restarting the computer, but the same problem happened after reboot.  I also checked my Dell drivers and appear to have the latest drivers installed.

After uninstalling KB5005033, the problem went away and I haven't run into it since.  The issue I have now is that KB5005033 is a mandatory Windows update and it will finish installing again next time I restart.  Is anyone else having similar problems?  Any recommendations on how to permanently resolve?

Thanks

I've had no issues with that set of patches installed

guys @DerekSeymour @mazzinia , I don't know what's wrong with @speedstep sincerely.

Apparently I solved the problem setting the ethernet adapter using this guide here:

https://answers.microsoft.com/en-us/windows/forum/all/cant-save-ip-settings-check-one-or-more-settings/e1168898-a0ff-4af3-80ad-58519edd91d1

briefly is: Network Status>Change Adapter Options, then double click on the Ethernet card, Properties>Internet Protocol Version 4 (TCP/IPv4)

then I put there what I got from ipconfig -all (I used the command in the command prompt when everything was "working"), I changed the 192.168... address adding like 5 or 6 numbers to the last number (my subnet mask is 255.255.255.0) and also used the Google DNS (8.8.8.8, 8.8.4.4).

Apparently everything works perfectly, I also ran a root.kit removal tool of Kaspersky just in case, and found nothing thankfully.

I'll get back to you if I have any updates for the worse, but right now everything is stable.

Thanks

@Gonin138 

Your OS is stuck July 29, 2021 KB5004296 BUILD 19041.1151

https://www.catalog.update.microsoft.com/Search.aspx?q=KB5004296

Your device is missing important security and quality fixes 0x80073712

https://support.microsoft.com/en-US/windows/windows-update-troubleshooter-for-windows-10-19bc41ca-ad72-ae67-af3c-89ce169755dd

KB5005033 (OS Builds 19041.1165, 19042.1165, and 19043.1165) is current for 21H1.

I did a full nuke and pave install and all updates today.

I @speedstep would say rootkit winsock malware is in place.

And its messing not only with your Internet but your clock as well so you do not get current updates.

Scanning won't find this because the root kit resides on a partition table and or partition that the end user does not see.

Its loaded BEFORE the os boots.