yahoo-eng-team team mailing list archive

[OpenStack Infra <2115510@xxxxxxxxxxxxxxxxxx>]

Reviewed:  https://review.opendev.org/c/openstack/os-ken/+/953631
Committed: https://opendev.org/openstack/os-ken/commit/bf639392f3dea7909792e257b8b65234dc5210a1
Submitter: "Zuul (22348)"
Branch:    master

commit bf639392f3dea7909792e257b8b65234dc5210a1
Author: Amoo <anas.jouhdy@xxxxxxxxx>
Date:   Fri Jun 27 19:11:09 2025 +0200

    Fixing the BGP loop prevention
    
    The method _is_looped_path_attrs did not return True when a BGP loop was detected.
    This had the effect of not rejecting the new route learn by the peer even though the local AS was in the AS Path.
    
    Closes-Bug: #2115510
    Change-Id: Icf346e1aa99f526f416ff1422fa0bd4cfd1ba438
    Signed-off-by: Amo <anas.jouhdy@xxxxxxxxx>


** Changed in: neutron
       Status: In Progress => Fix Released

-- 
You received this bug notification because you are a member of Yahoo!
Engineering Team, which is subscribed to neutron.
https://bugs.launchpad.net/bugs/2115510

Title:
  [neutron][os-ken] Bug on the BGP loop prevention

Status in neutron:
  Fix Released

Bug description:
  There is a bug in the method _is_looped_path_attrs defined here [1] and called only once here [2].
  In the case we found a loop, we should return True instead of None.

  
  More context:

  This can be reproduced with an external peer that re-advertise the
  routes learned from the OpenStack BGP speaker, in my case the external
  peer is an Cumulus switch in version 5.5.1.

  In the neutron-bgp-dragent log file we can see the error message
  "AS_PATH on UPDATE message has loops", but the external path was still
  added to the possible paths.

  
  OpenStack version: 2024.2
  Linux distro: Rocky 9.5
  Deployment mechanism: Kolla-ansible

  [1]:
  https://opendev.org/openstack/os-ken/src/branch/master/os_ken/services/protocols/bgp/peer.py#L1655

  [2]:
  https://opendev.org/openstack/os-ken/src/branch/master/os_ken/services/protocols/bgp/peer.py#L1569

To manage notifications about this bug go to:
https://bugs.launchpad.net/neutron/+bug/2115510/+subscriptions