Last Modified: Nov 07, 2022
Known Affected Versions:
15.0.0, 15.0.1, 188.8.131.52, 184.108.40.206, 220.127.116.11, 18.104.22.168
Opened: Jan 11, 2019 Severity: 5-Cosmetic
On BIG-IP, if a Mellanox virtual function is used along with DPDK, an 'ethX' device is present as a Linux device. Attempts to attach to this with tcpdump do not result in any packets being captured.
Confusion when a device is observed in Linux and an attempt is made to capture on it. In most cases, before attaching to a device the tmm causes the kernel module to detach from it, which removes the 'ethX' device. However, due to an implementation detail of the Mellanox DPDK support, this is not possible for these NICs.
-- BIG-IP Virtual Edition (VE) with a Mellanox virtual function and DPDK selected as the driver. -- Specify the kernel interface (ethX) rather than the tmm's interface (1.X) when running tcpdump.
Run tcpdump against the tmm interface (1.1, 1.2, etc) that corresponds to the device in question rather the kernel interface. This allows capture of the desired packets.