Is "Disable LLMNR" safe to switch on?

A standard hardening setting. It is not a latency tweak. The main cost: On a network without a local DNS server, reaching another PC by its name alone can fail. Its IP address still works.

Switch the tweak off in Frozen Tweaks. Switching it off puts back exactly what was there before, value for value.

Is "Disable LLMNR" free in Frozen Tweaks?

It is part of Frozen Pro and Elite. You can also make the change by hand with the values on this page.

EnableMulticast 0: disabling LLMNR in Windows

Frost LIVENetworkProUndo: YesUpdated Oct 8, 2026View as Markdown

Short answer

Updated Oct 8, 2026

LLMNR lets PCs on the same network resolve each other's names by multicast when DNS has no answer. It is also a well known route for spoofing attacks. The EnableMulticast policy set to 0 turns it off. In the registry it sets EnableMulticast to 0 under HKLM\SOFTWARE\Policies\Microsoft\Windows NT\DNSClient.

In the app

Disable LLMNRPRO

Registry

HKLMSOFTWARE\Policies\Microsoft\Windows NT\DNSClient

EnableMulticastYour previous value0

What the switch writes. Your current value may differ.

What it does

In the app the switch is called "Disable LLMNR", described there as: Turns off legacy multicast name lookups: less broadcast traffic and one known spoofing route gone.

When it helps, and when it hurts

When it helps

Security on shared networks, and slightly less multicast traffic.

When it hurts

On a network without a local DNS server, reaching another PC by its name alone can fail. Its IP address still works.

What it writes

Exactly what the switch changes, read from the app's source. Switching it off is what the app writes when you turn the tweak off again.

Registry values the switch writes.
Key and value	With the tweak	Switching it off
HKLMSOFTWARE\Policies\Microsoft\Windows NT\DNSClientEnableMulticast	0	Your previous valueSaved before the change, or deleted if there was none.

From the app's source (pack_extra.hpp), app 2.0.0, checked Oct 8, 2026.

The same change by hand

You do not need the app for this one. These commands make the changes from the table above. Run them in a Command Prompt opened as administrator, and make a restore point first.

Make the change · CMD

reg add "HKLM\SOFTWARE\Policies\Microsoft\Windows NT\DNSClient" /v "EnableMulticast" /t REG_DWORD /d 0 /f

See what it is set to now · CMD

reg query "HKLM\SOFTWARE\Policies\Microsoft\Windows NT\DNSClient" /v "EnableMulticast"

How to undo it

In the app: Yes

Switching it off puts back exactly what was there before, value for value.

Switch the tweak off in Frozen Tweaks. The app saved what each value was before the change and writes exactly that back, or removes the value if it did not exist.

Changing several settings at once? The app's Make a restore point button, on every plan, makes a Windows restore point before you start.

Verdict

A standard hardening setting. It is not a latency tweak.

Questions

What does the "Disable LLMNR" tweak change in Windows?: In the registry it sets EnableMulticast to 0 under HKLM\SOFTWARE\Policies\Microsoft\Windows NT\DNSClient.
Is "Disable LLMNR" safe to switch on?: A standard hardening setting. It is not a latency tweak. The main cost: On a network without a local DNS server, reaching another PC by its name alone can fail. Its IP address still works.
How do I undo it?: Switch the tweak off in Frozen Tweaks. Switching it off puts back exactly what was there before, value for value.
Is "Disable LLMNR" free in Frozen Tweaks?: It is part of Frozen Pro and Elite. You can also make the change by hand with the values on this page.

In the app