neutron

[OVN] Duplicated multicast packets on external network

Bug #1933207 reported by Lucas Alvares Gomes
6
This bug affects 1 person
Affects Status Importance Assigned to Milestone
neutron
Fix Released
Medium
Lucas Alvares Gomes

Bug Description

Reported at: https://bugzilla.redhat.com/show_bug.cgi?id=1949460

VMs subscribed to a multicast group are receiving 2 multicast packets when only one is sent by a sender VM.

I dug into the problem and found out that the problematic option is "mcast_flood" set in the localnet port types (provider network port) by ML2/OVN. Setting it to "false" fix the duplication problem.

The QE team upstream ran our downstream tests against an environment with that option disabled and everything worked fine. I think we should fix it upstream as well.

Note, the problematic option is the "mcast_flood". A similar option called "mcast_flood_reports" should still be enabled.

Lucas Alvares Gomes (lucasagomes)
Changed in neutron:
assignee: nobody → Lucas Alvares Gomes (lucasagomes)
status: New → Confirmed
importance: Undecided → Medium
Revision history for this message
OpenStack Infra (hudson-openstack) wrote : Fix proposed to neutron (master)

Fix proposed to branch: master
Review: https://review.opendev.org/c/openstack/neutron/+/797418

Changed in neutron:
status: Confirmed → In Progress
Akihiro Motoki (amotoki)
tags: added: ovn
Revision history for this message
OpenStack Infra (hudson-openstack) wrote : Fix merged to neutron (master)

Reviewed: https://review.opendev.org/c/openstack/neutron/+/797418
Committed: https://opendev.org/openstack/neutron/commit/953eb92a4f1d686a45d91100c8b02f9fe0771ed9
Submitter: "Zuul (22348)"
Branch: master

commit 953eb92a4f1d686a45d91100c8b02f9fe0771ed9
Author: Lucas Alvares Gomes <email address hidden>
Date: Tue Jun 22 10:54:13 2021 +0100

    [OVN] Disable mcast_flood on localnet ports

    The mcast_flood option will unconditionally forward multicast traffic
    for that port, this behavior is not desired and results in duplicated
    traffic being sent to the same port. This patch disables that behavior
    by setting the mcast_flood option for the localnet ports to False.

    Note that, a similar option called "mcast_flood_reports" is still
    enabled because we do want to have the multicast reports being sent but
    not normal traffic.

    Change-Id: I8033e12f5b30e3ecc9143431543266a890fe4073
    Closes-Bug: #1933207
    Signed-off-by: Lucas Alvares Gomes <email address hidden>

Changed in neutron:
status: In Progress → Fix Released
Revision history for this message
OpenStack Infra (hudson-openstack) wrote : Fix proposed to neutron (stable/wallaby)

Fix proposed to branch: stable/wallaby
Review: https://review.opendev.org/c/openstack/neutron/+/797813

Revision history for this message
OpenStack Infra (hudson-openstack) wrote : Fix proposed to neutron (stable/victoria)

Fix proposed to branch: stable/victoria
Review: https://review.opendev.org/c/openstack/neutron/+/797814

Revision history for this message
OpenStack Infra (hudson-openstack) wrote : Fix proposed to neutron (stable/ussuri)

Fix proposed to branch: stable/ussuri
Review: https://review.opendev.org/c/openstack/neutron/+/797815

Revision history for this message
OpenStack Infra (hudson-openstack) wrote : Fix merged to neutron (stable/wallaby)

Reviewed: https://review.opendev.org/c/openstack/neutron/+/797813
Committed: https://opendev.org/openstack/neutron/commit/0ff471aebab99eac16d649775f3f73958e8699c9
Submitter: "Zuul (22348)"
Branch: stable/wallaby

commit 0ff471aebab99eac16d649775f3f73958e8699c9
Author: Lucas Alvares Gomes <email address hidden>
Date: Tue Jun 22 10:54:13 2021 +0100

    [OVN] Disable mcast_flood on localnet ports

    The mcast_flood option will unconditionally forward multicast traffic
    for that port, this behavior is not desired and results in duplicated
    traffic being sent to the same port. This patch disables that behavior
    by setting the mcast_flood option for the localnet ports to False.

    Note that, a similar option called "mcast_flood_reports" is still
    enabled because we do want to have the multicast reports being sent but
    not normal traffic.

    Change-Id: I8033e12f5b30e3ecc9143431543266a890fe4073
    Closes-Bug: #1933207
    Signed-off-by: Lucas Alvares Gomes <email address hidden>
    (cherry picked from commit 953eb92a4f1d686a45d91100c8b02f9fe0771ed9)

tags: added: in-stable-wallaby
Revision history for this message
OpenStack Infra (hudson-openstack) wrote : Fix merged to neutron (stable/victoria)

Reviewed: https://review.opendev.org/c/openstack/neutron/+/797814
Committed: https://opendev.org/openstack/neutron/commit/5351d1b66bb269cdb22c23347fe939c359734ad1
Submitter: "Zuul (22348)"
Branch: stable/victoria

commit 5351d1b66bb269cdb22c23347fe939c359734ad1
Author: Lucas Alvares Gomes <email address hidden>
Date: Tue Jun 22 10:54:13 2021 +0100

    [OVN] Disable mcast_flood on localnet ports

    The mcast_flood option will unconditionally forward multicast traffic
    for that port, this behavior is not desired and results in duplicated
    traffic being sent to the same port. This patch disables that behavior
    by setting the mcast_flood option for the localnet ports to False.

    Note that, a similar option called "mcast_flood_reports" is still
    enabled because we do want to have the multicast reports being sent but
    not normal traffic.

    Change-Id: I8033e12f5b30e3ecc9143431543266a890fe4073
    Closes-Bug: #1933207
    Signed-off-by: Lucas Alvares Gomes <email address hidden>
    (cherry picked from commit 953eb92a4f1d686a45d91100c8b02f9fe0771ed9)

tags: added: in-stable-victoria
Revision history for this message
OpenStack Infra (hudson-openstack) wrote : Fix merged to neutron (stable/ussuri)

Reviewed: https://review.opendev.org/c/openstack/neutron/+/797815
Committed: https://opendev.org/openstack/neutron/commit/2c9803a8b4e395a1c2c0262987ebe21d8afb87a3
Submitter: "Zuul (22348)"
Branch: stable/ussuri

commit 2c9803a8b4e395a1c2c0262987ebe21d8afb87a3
Author: Lucas Alvares Gomes <email address hidden>
Date: Tue Jun 22 10:54:13 2021 +0100

    [OVN] Disable mcast_flood on localnet ports

    The mcast_flood option will unconditionally forward multicast traffic
    for that port, this behavior is not desired and results in duplicated
    traffic being sent to the same port. This patch disables that behavior
    by setting the mcast_flood option for the localnet ports to False.

    Note that, a similar option called "mcast_flood_reports" is still
    enabled because we do want to have the multicast reports being sent but
    not normal traffic.

    Change-Id: I8033e12f5b30e3ecc9143431543266a890fe4073
    Closes-Bug: #1933207
    Signed-off-by: Lucas Alvares Gomes <email address hidden>
    (cherry picked from commit 953eb92a4f1d686a45d91100c8b02f9fe0771ed9)

tags: added: in-stable-ussuri
Revision history for this message
OpenStack Infra (hudson-openstack) wrote : Fix included in openstack/neutron 16.4.0

This issue was fixed in the openstack/neutron 16.4.0 release.

Revision history for this message
OpenStack Infra (hudson-openstack) wrote : Fix included in openstack/neutron 17.2.0

This issue was fixed in the openstack/neutron 17.2.0 release.

Revision history for this message
OpenStack Infra (hudson-openstack) wrote : Fix included in openstack/neutron 18.1.0

This issue was fixed in the openstack/neutron 18.1.0 release.

Revision history for this message
OpenStack Infra (hudson-openstack) wrote : Fix included in openstack/neutron 19.0.0.0rc1

This issue was fixed in the openstack/neutron 19.0.0.0rc1 release candidate.

Revision history for this message
OpenStack Infra (hudson-openstack) wrote : Fix included in openstack/networking-ovn train-eol

This issue was fixed in the openstack/networking-ovn train-eol release.

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