yahoo-eng-team team mailing list archive

Thread
Date

[Bug 2123911] [NEW] GARP/ND packets ignored by the OF rules

To: yahoo-eng-team@xxxxxxxxxxxxxxxxxxx
From: Slawek Kaplonski <2123911@xxxxxxxxxxxxxxxxxx>
Date: Tue, 16 Sep 2025 07:51:58 -0000
Reply-to: Bug 2123911 <2123911@xxxxxxxxxxxxxxxxxx>
Sender: noreply@xxxxxxxxxxxxx

Public bug reported:

Bug originally reported at issues.redhat.com where a customer identified that a critical learn action was not updating openflow rules as it should during a bandwidth test that included a vxlan tunnel failover.
The failover caused a large mount of GARP/ND traffic from the new VXLAN tunnel, but OVS continued to send traffic to the old tunnel.

Upon investigation we found that in this situation OVS treated GARP/ND
traffic equally to all other traffic. If any packets happened to be
processed from the old tunnel after the failover garp packets were
received, the learn rule would just update the out of date return path.

Possible solution:
Modify the ML2/OVS interface to maintain GARP/ND rules along with learn actions.

Affected backend: ML2/OVS

** Affects: neutron
Importance: Medium
Assignee: Slawek Kaplonski (slaweq)
Status: Confirmed

** Tags: ovs

--
You received this bug notification because you are a member of Yahoo!
Engineering Team, which is subscribed to neutron.
https://bugs.launchpad.net/bugs/2123911

Title:
GARP/ND packets ignored by the OF rules

Status in neutron:
Confirmed

Bug description:
Bug originally reported at issues.redhat.com where a customer identified that a critical learn action was not updating openflow rules as it should during a bandwidth test that included a vxlan tunnel failover.
The failover caused a large mount of GARP/ND traffic from the new VXLAN tunnel, but OVS continued to send traffic to the old tunnel.

Possible solution:
Modify the ML2/OVS interface to maintain GARP/ND rules along with learn actions.

Affected backend: ML2/OVS

To manage notifications about this bug go to:
https://bugs.launchpad.net/neutron/+bug/2123911/+subscriptions