Sniff RoCE traffic on ConnectX-6

I’m trying to sniff RoCE traffic on a ConnectX-6 adapter.

As for ConnectX-5, Offloaded Traffic Sniffer feature is removed. So I used the mellanox/tcpdump-rdma Docker container. However, even the container does not work:

[root@nslrack05 /]# tcpdump -i mlx5_1

tcpdump: mlx5_1: No such device exists

(SIOCGIFHWADDR: No such device)

What am I missing? Thanks in advance.

Hello Mariano,

To sniff RoCE traffic with tcpdump, please review the information (for ConnectX-4 and above) provided below:–connectx-4-x

Information on installing and build tcpdump and libpcap below :

Download latest libpcap 1.10 and tcpdump 4.99 from

Extract, Configure, compile and install:

configure --enable-rdma --prefix=

make -j

make install

set LD_LIBRARY_PATH to use new pcap library

export LD_LIBRARY_PATH=/lib

Run command below to check if current tcpdump reports RDMA capable interfaces

tcpdump --list-interfaces |grep RDMA

Run RoCE traffic and tcpdump

tcpdump -i mlx5_0

If after reviewing the documentations above and you still have issue with issue with sniff RoCE traffic issue, please open a support case and we will provide further assistance. If you do not have a current support contract, please email the Nvidia team at to set up a valid support contract.

Thank you,

Nvidia Networking Support