[ovs-discuss] Debugging Packet Loss in Bridge

Klaus Darilion klaus.mailinglists at pernau.at
Wed Jun 13 08:54:05 UTC 2018


Hi!

I have the following problem. Server: Debian 9 with Proxmox 5.2.
Kernel: pve-kernel-4.15.17
OVS: 2.7.0-2

     VM
     tap100
      |
      |
    ovs-bridge
      |
      |
4x1G SUN NIC (niu.ko)
  |        |
server   server
 A         B


Packets from VM->server traverse the bridge fine. Packets from
servers->VM traverse the bridge only if they are approx < 1000 Bytes
(ping payload). For bigger packets I see them with tcpdump on the
physical interface, but not on the tap interface.

After some googling I found this issue:
https://github.com/torvalds/linux/commit/14224923c3600bae2ac4dcae3bf0c3d4dc2812be

The proxmox guys provided me with a new kernel where they backported
this patch.

Now, frankle, large packets from server-> VM work on one port of the
NIC, but not on the other port.

Now I am stuck, if my issue actually is related to the referenced
bugfix, or something else.

How can I debug why a packet does not traverse the bridge?

Thanks
Klaus





More information about the discuss mailing list