Do I understand it properly that I am not able to get information about TTL from IP header in any IP modes (IPRAW/UDP/TCP)?
So Sn_TTL register has TTL information from the last received IP packet? I talk about accessing TTL info for the packets being received, not sent. For example, to achieve task of tracing the route or assessing the distance to specific netowkring device.
I apologize for the late response.
In conclusion,Sn_TTL register is for sending packet. And the TTL of received packet don’t store .
If you need the TTL of received packet, I think you should be use MACRAW mode.