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LLMNR local name resolution

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Recommendation

Depends

Disable LLMNR if local devices are reachable via DNS or IP addresses and do not depend on name resolution through multicast queries.

If devices on the local network are found only by LLMNR name, after disabling, accessing them by name will stop working.

Main effect
Stopping LLMNR queries on the local network
Does not affect
mDNS and NetBIOS over TCP/IP

What changes

Section titled “What changes”

LLMNR (Link-Local Multicast Name Resolution) is a name resolution protocol on a local network without a DNS server. When Windows cannot find a name in DNS, it sends a multicast query to its neighbors; a computer that supports the protocol responds with its address. The BoosterX setting disables LLMNR: multicast queries of this kind are no longer sent, and local name resolution falls back to DNS.

Registry changes

Section titled “Registry changes”
Path Name Enabled Disabled
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Dnscache\Parameters EnableMulticast value deleted REG_DWORD 0

Disabling LLMNR writes REG_DWORD 0; reverting to the default state deletes the value, and the DNS Client starts using LLMNR by default again.

Exceptions and differences

Section titled “Exceptions and differences”

LLMNR is not the only way to find neighbors without DNS. Windows separately uses NetBIOS over TCP/IP and mDNS: the setting does not change them, so some older devices may still be found by name. The difference between the protocols is covered in detail in the study “AFD, IRP stack and NetBIOS”.

In corporate environments, LLMNR is often disabled centrally by the Group Policy “Turn off multicast name resolution”; on a home system without a DNS server, device availability depends on who responds to name queries.

How to verify the result

Section titled “How to verify the result”

  1. Before disabling, write down the name of a local device that is found without a DNS server, for example BOOSTERPC or the NAS name.

  2. Apply the disable and run ping by that name. If the device was visible only through LLMNR, the name will stop resolving; access by IP address will continue to work.

  3. Revert the setting and make sure name resolution is restored.

How to change and revert

Section titled “How to change and revert”

In BoosterX, open “Optimization” → “Security” → “Network, filters and DRM” → “LLMNR local name resolution” and move the toggle to “Enabled”: BoosterX will disable LLMNR. Click “Apply” at the bottom of the page; with “Instant apply” enabled, the change is applied immediately. To revert, move the toggle to “Disabled” and apply the change again: BoosterX will delete the value and restore the default Windows behavior.

Confirmation

Section titled “Confirmation”

Last checked: 2026-09-22.