[dpdk-dev] Unable to change source MAC address of packet

[Wiles, Keith]

> On Oct 27, 2016, at 6:33 AM, Padam Jeet Singh <padam.singh at inventum.net> wrote:
> 
> Hi,
> 
> I am crafting a packet in which the source MAC address as set in the Ethernet header is different than the transmit port’s default MAC address. A packet capture of the packets coming out of this port however comes with source MAC address of the port’s default MAC address.
> 
> Altering the destination MAC address works fine and shows up correctly in packet capture.
> 
> The underlying network interface is an i210 and some logs added to the eth_igb_xmit_pkts function show that the packets I have crafted indeed are reaching the driver with the source MAC address set in the packet code of the application.
> 
> How can I disable this automatic source MAC address setting?

The packets sent with rte_eth_tx_burst() are not forced to a give MAC address. If you are using something on top of DPDK like Pktgen or OVS or something, then it may try to force a source MAC address. Maybe the hardware does it, but we need to know the NIC being used and then someone maybe able to answer. I do not know of any Intel NICs do that.

Is this what you are doing.

> 
> Thanks,
> Padam

Regards,
Keith