The NXP switch tag is a proprietary header added to frames after the
source MAC address. The switch tag has 3 types, and different types
have multiple subtypes, the details are as follows.
- Forward NXP switch tag (Type=0) – Represents forwarded frames.
- SubType=0 - Normal frame processing.
- To_Port NXP switch tag (Type=1) – Represents frames that are to be
sent to a specific switch port.
- SubType=0 - No request to perform timestamping.
- SubType=1 - Request to perform one-step timestamping.
- SubType=2 - Request to perform two-step timestamping.
- To_Host NXP switch tag (Type=2) – Represents frames redirected or
copied to the switch management port.
- SubType=0 - Received frames redirected or copied to the switch
management port.
- SubType=1 - Received frames redirected or copied to the switch
management port with captured timestamp at the switch port where
the frame was received.
- SubType=2 - Transmit timestamp response (two-step timestamping).
Therefore, the length of different type switch tag is different, the
minimum length is 6 bytes, the maximum length is 14 bytes.
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Clark Wang <xiaoning.wang@nxp.com>
cdd82c7c71