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DTUS065 rev A.7 – June 27, 2014
V.6.2.3
Cloning
The ARPNAT solution loses the MAC address information from the wired
devices when bridging frames to the wireless interface. Most devices do not
care about MAC address substitution because they use the IP protocol in
Layer 3 and ARPNAT takes care of IP addresses.
But some devices do not use IP in layer 3 (PROFINET equipment, LAN
video camera…) and the MAC address is the unique ID identifying the
equipment correctly.
With the cloning feature, the WLn product can use the MAC address of a
wired equipment as the source MAC address on the wireless interface. The
cloned address is used for all wireless transactions: association,
authentication and data exchange. The original MAC address of the radio
card is ignored.
To set up the wireless MAC address, the WLn product clones the source
MAC address from the first incoming frame after a reboot. So, there should
be only one device connected to the WLn LAN.
If you mix the non IP device with other IP devices, you must ensure that the
non-IP device will send the first frame after the WLn product is turned on, to
be sure the WLn product will clone the correct MAC address. To avoid this
problem with a PROFINET equipment you should use the “PROFINET
cloning”, in which case the first PROFINET frame source MAC address will
be used for cloning.