Comment 9 for bug 1892362

Reviewed: https://review.opendev.org/747870
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=b7d3a9471c4f08d0a0513a1d6e66bb22c1be8429
Submitter: Zuul
Branch: stable/ussuri

commit b7d3a9471c4f08d0a0513a1d6e66bb22c1be8429
Author: Slawek Kaplonski <email address hidden>
Date: Fri Aug 21 13:15:34 2020 +0200

    Handle properly existing LLA address during l3 agent restart

    In case when L3 agent is hosting routers which have got subnets
    with Prefix Delegation enabled, agent couldn't properly handle
    IpAddressAlreadyExists exception raised when pd module tries to
    configure link local IPv6 addresses.

    Now this is fixed and L3 agent can restart without problems in such
    case.

    Change-Id: Icc995f7b2b465921e41342711d17539f16ead0ce
    Closes-Bug: #1892362
    (cherry picked from commit 81d375d39ab1affe4b0a29437eaabc387fb1c570)