Turn off LLMNR name resolution — via Microsoft Learn
LLMNR is a fallback where, when DNS fails, your PC asks every device on the local network who owns a name. Microsoft's security baseline recommends turning it off, which removes one way for a device on the same network to answer pretending to be the name you asked for.
Restart the computer
Group Policy
Open gpedit.msc (Pro, Enterprise and Education only) and go to:
Computer Configuration > Administrative Templates > Network > DNS Client > Turn off multicast name resolution = Enabled
Registry equivalent
Double-click a .reg file and confirm to merge it. Right-click → Edit first if you want to read it, which is always a good idea with any .reg file from the internet.
Apply
Windows Registry Editor Version 5.00
; Oddbyte.Me: Turn off LLMNR name resolution
[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\DNSClient]
"EnableMulticast"=dword:00000000Undo
Windows Registry Editor Version 5.00
; Oddbyte.Me: undo Turn off LLMNR name resolution
[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\DNSClient]
"EnableMulticast"=-Same thing from a command prompt
Run in an administrator Command Prompt or Terminal.
reg add "HKLM\SOFTWARE\Policies\Microsoft\Windows NT\DNSClient" /v "EnableMulticast" /t REG_DWORD /d 0 /fUndo:
reg delete "HKLM\SOFTWARE\Policies\Microsoft\Windows NT\DNSClient" /v "EnableMulticast" /fNormal DNS keeps working. On a small home network you may then need IP addresses or full names to reach other PCs. Microsoft documents this policy for Pro and higher editions.
Sources
- Policy CSP - ADMX_DnsClient: Turn_Off_Multicast — by Microsoft Learn
- Windows security baseline — Turn off multicast name resolution — by Microsoft Learn
- Administrative Templates (.admx) for Windows 11 2025 Update (25H2) — ADMX policy definitions — by Microsoft
- Source reviewed
- 2026-11-02
- Link checked
- 2026-11-02
- Tested hands-on
- Not by Oddbyte.Me
Oddbyte.Me hasn't tried this on every Windows build, so keep the undo handy.