---
issues:
  - In kernels < 3.19 ``net.ipv4.ip_nonlocal_bind`` sysctl option was not
    isolated to network namespace scope. L3 HA sets this option to zero to
    avoid sending gratuitous ARPs for IP addresses that were removed while
    processing. If this happens, then gratuitous ARPs will be sent.  It may
    populate ARP cache tables of peer machines with wrong MAC addresses.
fixes:
  - Versions of ``keepalived`` < 1.2.20 don't send gratuitous ARPs when
    keepalived process receives a ``SIGHUP`` signal. These versions are not
    packaged in some Linux distributions like Red Hat Enterprise Linux 7,
    CentOS 7, or Ubuntu Xenial. Not sending gratuitous ARPs may lead to peer
    ARP cache tables containing wrong entries about floating IP addresses until
    those entries are invalidated.  To fix that scenario, Neutron now sends
    gratuitous ARPs for all new IP addresses that appear on non-HA interfaces
    in router namespaces. This behavior simulates behavior of new versions of
    ``keepalived``.
