[dpdk-users] Weird phenomenon involving KNI

DoHyung Kim dohyung.kim at fluidic.io
Tue Jan 1 11:04:45 CET 2019

It was a consequence of the well-known behavior of Linux kernel regarding
ARP handling when multiple NICs are on the same subnet.

Thanks for all who have spent one's time looking into my question.


2018년 12월 31일 (월) 오후 6:42, DoHyung Kim <dohyung.kim at fluidic.io>님이 작성:

> I'm on the latest revision of 17.11 w/ a 2-port Intel X540 NIC. And having
> some trouble. one of the 2 ports is bound to a uio_pci_generic, and a KNI
> interface is up and assigned the MAC address of the port and an IP address,
> while the other port is kept intact bound to the kernel.
> Initially the 2 ports are known by their own IP addresses. But a few dozen
> seconds later, the latter port begins to report via ARP it has the IP
> address originally assigned to the KNI interface. So my DPDK app doesn't
> receive any of packets sent to the IP address assigned to the KNI interface.
> If I set the latter port down w/ ifdown and start my DPDK app, then my app
> receives packets as intended. But when I set the normal port up again, then
> it doesn't receive any packet since, this time, the KNI announces via ARP
> it has the IP address of the other port too.
> I searched for solution in DPDK mailing lists for this problem, but
> instead found a few posts mentioning KNI will be replaced w/ something
> else. But it seems that it's still gaining functionalities over the
> releases. So I'm confused.
> Please inform me of any clue for solving the problem described above. Or
> should I fallback to something more stable like TAP driver?
> Thanks in advance.
> --
> DoHyung Kim
> Fluidic Inc.

DoHyung Kim
Fluidic Inc.

More information about the users mailing list