Hello, all！
I am using SJA1110 as a switch chip and trying to capture the first hop sending delay of an end nodeSo I am considering using the trap-to-host feature of this switch to get the timestamp of when the packet arrives at the switch port. But after configuration, it never captures the trap-to-host management frames at the M7 core. The network topology is: endpoint 1 -> (P1) SJA1110 (P5) -> endpoint 2, with the intention of testing the sending delay from endpoint 1 to port P1.
The configuration is as follows:
1. disable the L2 lookup learning;
2. FL_DOMAIN of the L2 Forwarding Table of ports P1 and P5 are all turned off;
3. configure a static L2 Look Entry from P5 to P1 for ARP reply back to endpoint 1;
4. configure a DPI rule over ipv4.
The phenomena is as follows:
1. when adding DESTPORT -- P5 to the DPI rule in config:4, udp packets from endpoint 1 can be captured on endpoint 2;
2. when clearing DESTPORT of this DPI ruel, udp packets from endpoint 1 cannot be captured on endpoint 2.
As you can see from these two items, the DPI rule should work. However:
3. when the TAKETS, TRAP and VALID flag of the DPI rule are enabled, the trap-to-host switch-header-trail frame cannot be captured on the M7 core of the SJA1110
By the way, the gPTP stack is enabled and the PTP frame [using DPI rule trap to host] can be captured and delivered to GPTP_PORT_MsgReceive() interface on M7 core.
Thank you for watching and I look forward to your interest and answers !!!!!!
