The Windows 10 workstation is missing DNS after changing from the built-in NIC to a PCI NIC.
The Windows 10 workstation is missing DNS after changing from the built-in NIC to a PCI NIC.
Old workstation was getting intermittent disconnects on its decade-old onboard NIC, so I installed a new PCI NIC, which was working great at first, but suddenly Windows now refuses to do a DNS lookup.
This workstation runs some developer services and is assigned a static IP by the router.
After a week or so of working fine, Windows complained today because the static IP address was already used on the old network adapter. So, I made sure they were both set to DHCP, de-allocated the old MAC on the router, and allocated the new one to the same static IP.
The workstation has full connectivity to the LAN, I can even SSH to another host and make a request out to the Internet from there.
Every other machine on my LAN can get to the Internet just fine.
If I ping a WAN IP address directly, Windows is okay with that.
If I look up a domain on the command line with `nslookup`, that works, too.
But if I try to actually pull up google.com or whatever in my browser, or ping it by domain name instead of by IP address, OR use the PowerShell Dns lookup utility, all I get is timeouts and errors.
I've flushed my DNS cache, I've done a full network reset which uninstalls and reinstalls all network adapters to factory defaults, I've even rebooted into safe mode to see if that made a difference. I've restarted the desktop itself and the router a good half-a-dozen times now.
I'm also quite baffled that `nslookup` works fine whichever DNS server I pass as the second argument, but opening PowerShell and trying the same domain and server with `Resolve-DnsName` or `[System.Net.Dns]::GetHostEntry()` give me timeout errors.
What is going on?? I've never encountered this situation before. Windows configures its default DNS on this adapter to 192.168.1.254, which is the router, but if I force it to use 8.8.8.8 or other public DNS, it doesn't make a difference.
There are no proxies configured. The browser alone cannot perform a DNS lookup; only nslookup works on Windows. Updates, game clients, and other programs stop functioning.
Here is the output from the ipconfig /all command:
Windows IP Configuration
Host Name . . . . . . . . . . . : CHERNO-ALPHA
Primary Dns Suffix . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : attlocal.net
Ethernet adapter PCI NIC (Installed 2025):
Connection-specific DNS Suffix . : attlocal.net
Description . . . . . . . . . . . : Realtek PCIe 2.5GbE Family Controller
Physical Address. . . . . . . . : BC-07-1D-6F-FA-11
DHCP Enabled. . . . . . . . : Yes
Autoconfiguration Enabled . . . : Yes
IPv6 Address. . . . . . . . . : 2600:1700:7aa1:e0b0::46(Preferred)
Lease Obtained. . . . . . . . . : Monday, November 3, 2025 8:04:24 PM
Lease Expires . . . . . . . . : Tuesday, November 4, 2025 12:04:23 AM
IPv6 Address. . . . . . . . . : 2600:1700:7aa1:e0b0:d542:60ad:fd54:7858(Preferred)
Temporary IPv6 Address. . . . . : 2600:1700:7aa1:e0b0:dcc6:8447:d48a:2cbc(Preferred)
Link-local IPv6 Address . . . . : fe80::318f:c727:f677:68b0%8(Preferred)
IPv4 Address. . . . . . . . . : 192.168.1.200(Preferred)
Subnet Mask . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . : Monday, November 3, 2025 8:04:23 PM
Lease Expires . . . . . . . . . : Tuesday, November 4, 2025 8:04:22 PM
Default Gateway . . . . . . . . . : fe80::a9b:b9ff:fed7:1472%8
192.168.1.254
DHCP Server . . . . . . . . . . : 192.168.1.254
DHCPv6 IAID . . . . . . . . . . : 263980829
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-2B-84-A7-52-F0-79-59-8F-39-EE
DNS Servers . . . . . . . . . . : 2600:1700:7aa1:e0b0::1
192.168.1.254
Preferred IPv6 Address. . . . . : 2600:1700:7aa1:e0b0:d542:60ad:fd54:7858
Connection-specific DNS Suffix Search List:
attlocal.net
attlocal.net
Did you turn off the onboard NIC? What was the TRACERT 8.8.8.8 result?
==
OK. NSLookup functions but DNS Client seems to be inactive.
Check if the DNS Client service is disabled or has issues.
Also review Event Viewer - Administrative Views.
==
Consider running a Windows 10 repair. Refer to: https://www.youtube.com/watch?v=FS6GRiIOoCk
What's unusual is that the nslookup command functions properly, but other tasks are problematic.
From your ipconfig output, it seems an IPv6 DNS server is configured. Try turning off IPv6 and observe any changes.
I suspect you didn't include IPv6 addresses in the NSLOOKUP query when testing... I haven't even attempted that, so I'm uncertain if it's effective.
IPv6 generally introduces more complications than benefits.
Only a handful of websites exclusively use IPv6 in their configuration.
I usually recommend disabling it.
DNS client is active:
The previous NIC card was fully removed from the Device Manager:
Nonetheless, upon restarting it reappears:
IPv6 is turned off:
Yet it also restarts after a reboot:
tracert 8.8.8.8 hangs endlessly at the router and needs to be terminated with Ctrl + C, although pinging it functions properly:
An unusual observation is that, despite IPv6 being disabled, nslookup defaults to using an IPv6 DNS server. If I provide my router's IP address directly as the second argument, the response changes from "UnKnown" to "dsldevice" and it shows an IPv4 address:
Another oddity is that I can still communicate with others via Signal Desktop on this device. I believe this is because the Signal Messenger client stores certain IP addresses in memory, eliminating the need for a DNS lookup.
Regarding the system log, Windows indicates that "none of the configured DNS servers responded":
There should be a fix here, since the machine clearly has network connectivity and there must be some faulty or corrupted DNS data, or perhaps IPv6 settings have become unresponsive.
Use the Get-NetAdapter cmdlet to explore installed network adapters.
Please follow the examples carefully and take your time.
Copying the example from the provided link into PowerShell as an administrator is recommended.
The goal is to understand what Windows detects about the network adapters installed.
I gathered all the properties for both the previous and current adapters, and compared them. Apart from the clear distinctions such as name and speed (the old one was disconnected), the significant variations were:
- The new NIC adapter's FullDuplex setting is True, while the old one had it set to empty
- The HigherLayerInterfaceIndices value changed from {17} to {19} in the new version
- Both versions are stored here for future reference:
https://gist.github.com/changemewtf/ab6b...624fa6a150
Details about the hardware:
Turn off the onboard NIC in the BIOS or Control Panel - Network And Sharing Center, adjust the adapter settings, then right-click the adapter and disable it instead of uninstalling it. If you simply remove it, it will reinstall automatically. If you can't even run tracert, it suggests a broader internet connectivity issue, not just a DNS problem. You should be able to ping or tracert 1.1.1.1 / 8.8.8.8 / 9.9.9.9, as these are public DNS servers.
Onboard NIC is turned off in BIOS yet no visible change. It still doesn’t show up in the Network Connections adapter list. I can reach any valid IP address without issues. DNS remains the only issue—I’m able to ping those servers and even chat with a friend via Signal Messenger, likely because the server IPs are cached locally. Booting into a live Ubuntu USB works perfectly for internet access, indicating the problem is tied to DNS lookups on this particular Windows machine.