We rely on keepalived to send gratuitous ARPs when floating IP is added.
Older versions of keepalived up to 1.2.20 (exclusive) contain bug [1] where
keepalived does not send GARP on receiving SIGHUP. Unfortunately, newer
versions containing the fix are not packaged yet for some distributions
like RHEL or CentOS or Ubuntu Xenial, so this patch adds a workaround for
such distributions until new packages are available.
The patch also sets net.ipv4.ip_nonlocal_bind kernel parameter to 0 for
Snat and HA router namespaces in order to avoid sending gratuitous ARPs
for IP addresses that are not bound to the interface anymore - possibly
because of failover or removal. Note that kernel < 3.19 contain a bug
where this knob is missing. In case it attempts to set the parameter and
it's missing on the system, it doesn't set the knob in root
namespace like it's done for fip namespaces, but only issues a warning
message.
[1] https://bugzilla.redhat.com/show_bug.cgi?id=1391553
Change-Id: Ieab53624dc34dc687a0e8eebd84778f7fc95dd77
Closes-bug: 1639315
4fdd89e94f