VLAN priority (802.1q PCP)

Hi,

for a network test application (TSN), I need to set the priority tag in outgoing vlan-tagged frames. Is there a way to do this – either programmatically via socket or ioctl interface, or via network settings?

With Wireshark, I can see ingress vlan-tagged frames with PCP field set – so my adapter (VIVANCO IT-USBC NET1000) supports it.

On Linux, I use SOL_SOCKET, SO_PRIORITY, which does the job. Unfortunately, SO_PRIORITY is not available on OS X, at least not up to 10.13.5.

Any help is welcome!

Thanks, Bernd