Advanced-mac

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MAC Address

The MAC Address menu has settings to let you electronically change (or "spoof") the MAC (Media Access Control) Address of various network interfaces. This function does not change the factory-assigned MAC Address in the device's chip. It just overlays a different address in software.

A MAC address is called a Universally Administered Address (UAA) when it's set by the manufacturer or a locally-administered addresses (LAA) when it is assigned by a System Administrator.


The first three octets (group of eight bits) are the Organizationally Unique Identifier (OUI). The OUI is a 24-bit number that identifies the manufacturer, organization, or vendor. The last three pairs of digits are the number specific to the device, known as Network Interface Controller (NIC)-specific portion of the address.

For common device names in Tomato64, see the FAQ page.

How Default WAN MAC Addresses are Derived

Since release 2021.8, the way Tomato64 configures the default MAC Address for the WAN Port (based on the eth0 / LAN MAC Address) has changed.

Tomato64 now sets wanX MAC Addresses as follows:

  • WAN => eth0 MAC + (decimal) 16 [in releases 2021.7 and older: eth0 = MAC + 1 (decimal value)]
  • WAN2 => eth0 MAC + (decimal) 17
  • WAN3 => eth0 MAC + (decimal) 18
  • WAN4 => eth0 MAC + (decimal) 19

For example, on a router with LAN hardware MAC Address of 2C:30:33:DB:F7:CC, Tomato64 would now set the WAN MAC Address to 2C:30:33:DB:F7:DC, (by adding CC + 16). In releases 2021.7 and older, Tomato64 would have configured the default WAN MAC Address as 2C:30:33:DB:F7:CD (by adding CC + 1).


This is further illustrated in the following screenshots.


A WAN MAC Address, as Configured in Tomato64 2021.8 and newer:




A WAN MAC Address, as Configured in Tomato64 2021.7 and earlier:


For **Tomato64 2021.7 and older: the above image shows the default MAC Address calculated and set in the GUI. Tomato64 will initially display a dfifferent MAC Address (after an "erase all data in NVRAM memory thorough" has been done). The discrepancy will be fixed in release FT 2022.1 .
 WAN Port:** In this field, you can enter any valid MAC Address to be assigned to the WAN interface.

  • Default - This option leaves the fixed, factory-assigned MAC Address as the interface's MAC Address.
  • Random - This option assigns a random MAC Address to the device.
  • Clone PC - This assigns the same MAC Address used by the interface of the client currently connecting to Tomato64's web admin interface.

Some cable and other Internet providers authorize your cable modem and devices based on its MAC address. Every network has a unique address.
When your modem requests an address from the Internet provider's DHCP server, the Internet provider will either grant it or deny it access to the network based on it's MAC Address.

Some cable companies also authenticate the network card in your PC/client device after you've logged onto their network. They do this to prevent you from using any LAN client device other than the first one you used (whose MAC Address is regstered with them) using their service with out paying for it. By doing so, they can force you to use the same client device you've always used.

If the provider's network detects a different MAC Address than the one associated with the original client device, it will deny your client device access to the network. It will only allow devices known to them, in good standing. However, If you let Tomato64 clone your original client device's network MAC Address, it will fool your cable provider into thinking you're still using the same PC/client device interface to access their services, and your router will be allowed on their network. They don't really care which device you use, the MAC is actually associated to your billing account. Often, if you call them and tell them you have a new device, they will change the MAC Address record in their system.


    • Wireless Interface eth1: **In this field, you can enter any valid MAC Address to be assigned to wireless interface eth1.
  • Default: This option leaves the fixed, factory-assigned MAC Address as

the interface's MAC Address.

  • Random: This assigns a random MAC Address to the device interface.
  • Clone PC: This assigns the same MAC Address used by the interface of the client

currently connecting to Tomato64's web interface.

    • Wireless Interface eth2: **In this field, you can enter any valid MAC Address to be assigned to wireless interface eth2.
  • Default: This option leaves the fixed, factory-assigned MAC Address

as the interface's MAC Address.

  • Random: This assigns a random MAC Address to the device interface.
  • Clone PC: This assigns the same MAC Address used by the interface of the client

currently connecting to Tomato64's web interface.

    • Wireless Interface wl0.1: **In this field, you can enter any valid MAC Address to be assigned to wireless interface wl0.1 (typically the first wireless VLAN).
  • Default: This option leaves the fixed, factory-assigned MAC Address as

the interface's MAC Address.

  • Random: Choosing this option assigns a random MAC Address to the device
  • Clone PC: This assigns the same MAC Address used by the interface of the client

currently connecting to Tomato64's web interface.



MAC Address Notes

Until at least release 2021.8, Tomato64 has a problem caused by changing the wireless MAC Address.

Changing the first 3 octets of the MAC Address can cause some issues such as wireless interfaces to drop. For details, please see:
https://bitbucket.org/pedro311/freshtomato-arm/issues/173/wl11-drops-and-upon-restart-attempt-all

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