Well my primary machine (windows 11) has decided it doesn't want to communicate.  I've been through the usual troubleshooting steps without any luck.

All other machines on the network are working fine, connecting, getting an IP & reaching the internet OK. So no issues with dsl modem & router.

The problem machine shows connection & internet access, then flashes to no internet access. Ipconfig responses often reporting the IP is a duplicate & the adapter is disconnected.  This occurs even when the machine has a reserved IP on the router. Problems occur whether the machine is using DHCP or a fixed address. Generally /release /renew end up with same or other non expected results.

The problem persists regardless of the adapter used, the built-in wifi, the built-in Ethernet adapter, or an external USB WiFi dongle.  All end up with the same problem.

I'm trying a roll back to a system restore point about a week back. If that doesn't work, I may have to try a repair install.

Years back I could just remove & reinstall the network stack, but that was before the borg...

That does not seem to be uncommon.  


At my work we have some win11 machines and they are WONKY compared to 10...  Good Luck.

Yeah, I get the duplicate IP address in ipconfig even after reserving an address for the adapter on the router that is outside the range of addresses used by DHCP.

Downloaded an iso of the current win11 install set & currently running a "repair" install that should leave files & apps intact.  Fingers crossed.

23H2
OS build 22631.3958
Windows Feature Experience Pack 1000.22700.1026.0


This AM it seems to be working with the USB dongle & a reserved IP on the router.    Same configuration that failed most all day yesterday.

Yesterday the initial failure occurred while posting a reply on this section & uploading a pic.

... and it's back.

Internet access started dropping out, returning, then dropping out again during an attempted post w/pic uploads.

Once again seeing the"Duplicate" tag on the ipv4 IP when Ipconfig /all is run.  The IP is a reserved IP on the router assigned to the adapter MAC & outside the range used for DHCP.


ETA:   Changed over to the machine's wifi card w/5 ghz connection.  Still got the "connected but no internet" thing & the duplicat IP flag while using a reserved, non-DHCP range address, linked to the MAC.    Went away for half & hour and when I looked at it again, it has internet connection again.     We'll see how long it lasts this time.

And to reiterate, this dropping internet thing is only happening on this windows machine.  Tablets, phone, other PC,  etc.  have zero interruption at the same point in time.

Don't know if this will last, but things seem to be working now.

I disabled the wireless adapters, re-enabled the ethernet card & connected a cable between it and a new router (TP-Link AC1200)  configured as a range extender.   Local connections via IP address were fine, but no internet access until I set the AC1200 to pass all DHCP, DNS & gateway functions back to the DSL+Router for handling instead of intercepting them.

Connections on the desktop are cleaner now.  Weird behaviour when running Fluidd has gone away & things are working fine.

Fingers crossed that it will stay this way.

good news that things are working better.
Often it is best to have one DHCP server to keep life simple. (and maybe a hot backup)

I have a few managed routers that depending on timing would help provide help
and become the DHCP server.  

My happiness was to provide specific ranges for IP addresses and make sure only one on
that network would provide the necessary services.  I standardized my config on the managed
routers so they no longer "helped" in DHCP services.

Most of the non-computer hardware I have the mac address -> IP address mapping done.