really, you MUST read this before you upgrade)

- Kube-proxy's IPVS proxy mode no longer sets the net.ipv4.conf.all.route_localnet sysctl parameter. Nodes upgrading will have net.ipv4.conf.all.route_localnet set to 1 but new nodes will inherit the system default (usually 0). If you relied on any behavior requiring net.ipv4.conf.all.route_localnet, you must set ensure it is enabled as kube-proxy will no longer set it automatically. This change helps to further mitigate CVE-2020-8558. ([...