On Mon, Sep 19, 2016 at 8:53 AM, Balazs Nemeth <balazs.nem...@ericsson.com> wrote: > Dear All, > > > > I think we found a bug in OVS master. In the test case 3 OVS is used, VXLAN > tunnels are configured among them in full mesh, so every node has 2 Tunnel > End Point (TEP). BFD is turned on for monitoring the tunnel liveness. In the > beginning, traffic and BFD messages are ongoing between all the nodes. If > you delete 1 TEP from node-1 (TEP13 towards node-3), then the remaining TEP > on node-1 (TEP12 towards node-2) will be affected also. I expect it to work > after deleting another TEP, but it does not transmit packets. It will not be > able to terminate VXLAN encapsulated packets any more! Due to this the BFD > Forwarding status of the remaining TEP will go to False, and traffic will be > dropped between this TEP and the another TEP of this remaining tunnel. I > also see that dpctl flows for remaining tunnel will disappear after 10 sec. > > > > I think when you delete one TEP from the two, some data or setting of the > remaining TEP will be overwritten improperly. Due to RFC 7348, OVS will > accept VXLAN encapsulated packets on UDP dst_port 4789 by default. Perhaps > this dst_port value will be overwritten. I made a port-mirroring on the > physical interface and I can see packets like: > > d6:ee:ac:b9:6c:81 > 00:23:20:00:00:01, ethertype IPv4 (0x0800), length 66: > 169.254.1.1.49186 > 169.254.1.0.3784: BFDv1, Control, State Down, Flags: > [none], length: 24 > > a0:36:9f:43:f2:f8 > a0:36:9f:43:f3:d8, ethertype IPv4 (0x0800), length 144: > 10.85.46.4 > 10.85.46.7: ICMP 10.85.46.4 udp port 4789 unreachable, length > 110 > > > > The issue can be fixed if you change any parameter of the remaining TEP. > After that TEP maybe reinitialized, and traffic can go through (BFD > Forwarding will be True again), e.g. chaging remote_ip to random value and > back: > > 1. node-1: ovs-vsctl set Interface TEP12 > options:remote_ip=10.85.46.254 > > node-1: ovs-vsctl set Interface TEP12 options:remote_ip=10.85.46.7 > > The issue can be fixed also e.g. with modifying dst_port of TEPs between > node-1 and node-2: > > 2. node-1: ovs-vsctl set Interface TEP12 options:dst_port=4790 > > node-2: ovs-vsctl set Interface TEP21 options:dst_port=4790 > > > > We are working on the fix, any help or tips would be appreciated.
I agree it sounds like a bug :) I haven't heard of this before, so I don't have any specific tips. We'll look forward to seeing the patch. _______________________________________________ discuss mailing list discuss@openvswitch.org http://openvswitch.org/mailman/listinfo/discuss
