Unable to Monitor Sending Speed on Mellanox NIC in Loopback Configuration

I’m using a Mellanox NIC with 2 ports, connected in a loopback configuration. I have two RDMA programs running: one sends data from one port, and the other receives it on the second port. While monitoring the speeds, I can only see the receiving speed, but not the sending speed, regardless of the tool I use (like tcpdump, nload, etc.). Can anyone explain why this is happening?

I am not sure if you are using ROCE or RDMA.

If you installed our MLNX driver, you can use ibdump (RDMA), tcpdump (ROCE) with correct libpcap version, mlnx_perf (statistics traffic counters).

Also for reference: (tcpdump requires a certain version of libpcap)


ESPCommunity (What is MLNX Perf)

You can test with our RDMA/ROCE perf test utilities ib_write/read/send_bw as well for comparison purpose.

sudo ibdump
Initiating resources …
searching for IB devices in host
Port active_mtu=1024
MR was registered with addr=0x561bce45fb90, lkey=0x183120, rkey=0x183120, flags=0x1

Device : “mlx5_0”
Physical port : 1
Link layer : Ethernet
Dump file : sniffer.pcap
Sniffer WQEs (max burst size) : 4096

Failed to set port sniffer1: command interface bad param

can you tell why is this happening?