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Zafer Balkan edited this page Apr 27, 2026 · 6 revisions

dzmac Help

This help content is adapted from the original TMAC help and limited to features currently supported by dzmac.

What is dzmac?

dzmac allows you to change, or spoof, the Media Access Control (MAC) address of a Network Interface Card (NIC) instantly. It provides a simple user interface and shows practical information about each NIC available on the machine.

Every NIC has a manufacturer-assigned MAC address hard coded into its hardware. Windows drivers normally use that address for Ethernet and LAN access. dzmac can set a new MAC address for the NIC so that Windows uses the configured value instead of the original hardware address.

For the current milestone, dzmac focuses on Windows 10 and Windows 11 on 64-bit systems.

How does dzmac work?

dzmac works by writing a value into the Windows registry.

When a network adapter is enabled, Windows checks for the NetworkAddress registry value under:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002bE10318}\[adapter-id]

If the value exists, Windows uses it as the MAC address. If it does not exist, Windows uses the original hardware MAC address provided by the manufacturer.

Some network adapter drivers also expose this capability directly in the advanced settings of the adapter properties in Windows Device Manager.

Why would someone use dzmac?

dzmac is useful when you need to test, validate, or temporarily change the MAC address presented by a network adapter. It is especially practical for administrators, lab users, and security professionals who need to work with adapter identity changes quickly and repeatedly.

How to change the MAC address of a network connection

  1. Select the target network connection in the main list.
  2. In Change MAC Address, enter a MAC address in hexadecimal format.
  3. Optional: click Random MAC Address to generate one.
  4. Optional: choose a vendor/manufacturer in the dropdown first, then generate a random MAC.
  5. Optional: enable automatic adapter reset/restart to apply changes.
  6. Click Change Now!.

How to restore the original MAC address

  1. Select the target network connection.
  2. In Change MAC Address, click Restore Original.

Why does setting the first octet to 02 help with some Wi-Fi MAC changes?

Some wireless adapter drivers may reject MAC changes unless the address is marked as locally administered. Setting the first octet to 02 sets the local-administered bit, for example 02:11:22:33:44:55, which often works as a practical workaround on adapters that ignore other values.

Use the Use '02' as first octet of MAC address checkbox in the GUI or -r02 on the CLI. If the change still does not appear, manually disable and re-enable the adapter, or use -re, and verify the active MAC again.

How to enable/disable a network connection

  1. Select the network connection in the list.
  2. Toggle the Enabled checkbox for that row.

How to refresh the network connection list

  • Use Options > Refresh, or
  • Press F5.

How to enable/disable DHCPv4 on a connection

  1. Select the network connection.
  2. Use Action > DHCPv4 > DHCPv4 Enabled to toggle DHCPv4.

Note: dzmac preserves the current IPv4 configuration when switching DHCPv4 modes (safe-by-default behavior).

How to release/renew an IPv4 DHCP lease

  1. Select the network connection.
  2. Use Action > DHCPv4 > Release IP or Renew IP.
  3. Wait for the operation to complete.

Can dzmac update the network card vendor list?

Yes. dzmac includes a vendor list update feature so you can download the latest vendor data, or OUI data, from IEEE.

Can dzmac configure any network adapter completely?

dzmac supports the currently implemented MAC and IPv4-related operations exposed by the GUI and CLI. Similar to the original TMAC, dzmac supports adapter and preset capabilities.

Can dzmac use presets or IPv6 configuration?

No, not in the current milestone. IPv6 and DHCPv6 are not planned.

Are there any adapters whose MAC address dzmac cannot change?

Yes. dzmac cannot change the MAC address of a Microsoft Network Bridge.

A Network Bridge automatically uses the original MAC address of the first NIC added to the bridge, with the first octet set to 0x02.

Command-line interface (CLI)

Usage:

dzmac -n network_connection_name [options]

MAC address options

  • -m [mac_address] set MAC address (empty value restores original)
  • -nm [mac_address] alias behavior equivalent to -m
  • -r random MAC from vendor list
  • -nr random MAC from vendor list (alias behavior)
  • -r02 random locally-administered MAC (02 first octet)
  • -nr02 random locally-administered MAC (alias behavior)

IPv4 options

  • -i ip/mask[,ip/mask...] set IPv4 addresses
  • -g gateway/metric[,gateway/metric...] set IPv4 gateways
  • -d dns[,dns...] set IPv4 DNS servers
  • -h enable DHCPv4
  • -rl release DHCPv4 lease
  • -rn renew DHCPv4 lease

Other options

  • -s silent mode flag
  • -re disable/enable adapter (reset)
  • -di disable adapter
  • -en enable adapter
  • -ro restore original MAC record used by dzmac
  • -help display CLI help

CLI examples

Apply a specific MAC and reset adapter:

dzmac -n "Ethernet" -m 00:01:02:03:04:05 -re

Apply random MAC (locally administered) and reset adapter:

dzmac -n "Wi-Fi" -r02 -re

Enable DHCPv4 on a connection:

dzmac -n "Ethernet" -h

Release then renew DHCPv4 lease:

dzmac -n "Ethernet" -rl
dzmac -n "Ethernet" -rn

Does the CLI expose all dzmac features?

The original TMAC description states that command-line options expose the entire software functionality, including presets. In dzmac, the CLI exposes the currently supported dzmac feature set documented on this page. Unsupported IPv6, proxy, and installer-related TMAC topics are intentionally excluded.

Features intentionally not supported in dzmac

The following TMAC help topics are intentionally out of scope for the current dzmac milestone:

  • DHCPv6 management (-h6, -rl6, -rn6, and other IPv6 write operations)
  • Internet Explorer / HTTP proxy management (-pxy and GUI proxy settings)
  • TMAC installer command-line help topics

My problem is not listed above

DZMAC writes logs to Windows Event logs. Review the logs to troubleshoot the problem. It may be either hardware, firmware or the driver that does not allow MAC address changes. But for more details, logs are your best resource. Check the Event Log Catalog page for a clearer understanding.

Notes

The content is derived from TMAC Help Page, but adjusted to reflect the currently supported dzmac feature set only.

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