My setup consists of one host with 100Gb Mellanox CX-5 NIC send traffic to a target with 25Gb Mellanox CX-4 NIC thought my network switch.
All of the elements in my systems have the ECN feature enabled.
I also have another server, with one 25Gb Mellanox CX4 NIC, set to monitoring the target switch port. On this server, I run Wireshark capture. Once the data transfer finishes, I cannot see any packet with ECN bit set to 11 even thought I can find the RoCEv2 CNP packets.
Checking the np_ecn_marked_roce_packets on the target side, I see that the counter is around 40000 packets. So I don’t understand why I cannot find the packet with ECN bit set to 11. On your article, I see that you can capture the packet with ECN = 11b.
I wonder if I need to configure the Mellanox NIC anyway to capture
the packets with ECN = 11b.
Thanks and best regards,