iptables -t nat -A ISTIO_POSTRT -m owner --socket-exists -p tcp -m set --match-set istio-inpod-probes-v4 dst -j SNAT --to-source 169.254.7.127
ip6tables -t nat -N ISTIO_POSTRT
ip6tables -t nat -A POSTROUTING -j ISTIO_POSTRT

                                      description: The time duration between keep-alive
                                        probes.
                                      type: string
                                    probes:
                                      description: Maximum number of keepalive probes
                                        to send without response before deciding the

iptables -t nat -N ISTIO_POSTRT
iptables -t nat -A POSTROUTING -j ISTIO_POSTRT

)

const (
	// to reliably identify kubelet healthprobes from inside the pod (versus standard kube-proxy traffic,
	// since the IP is normally the same), we SNAT identified host probes in the host netns to a fixed
	// APIPA/"link-local" IP.
	//
	// It doesn't matter what this IP is, so long as it's not routable and doesn't collide with anything else.
	//

	RouteTableInbound    = 100

	DNSCapturePort              = 15053
	ZtunnelInboundPort          = 15008
	ZtunnelOutboundPort         = 15001
	ZtunnelInboundPlaintextPort = 15006
	ProbeIPSet                  = "istio-inpod-probes"
)

var log = istiolog.RegisterScope("iptables", "iptables helper")

type Config struct {
	RestoreFormat bool `json:"RESTORE_FORMAT"`
	TraceLogging  bool `json:"IPTABLES_TRACE_LOGGING"`

- Fixed an issue where kubelet does not set case-insensitive headers for http probes. (#117182, @dddddai) ([#117324](https://github.com/kubernetes/kubernetes/pull/117324), [@dddddai](https://github.com/dddddai)) [SIG API Machinery, Apps and Node]

- `kubelet` allows pods to use the `net.ipv4.tcp_fin_timeout`, “net.ipv4.tcp_keepalive_intvl”
  and “net.ipv4.tcp_keepalive_probes“ sysctl by default; Pod Security Admission
  allows this sysctl in `v1.29+` versions of the baseline and restricted policies. ([#121240](https://github.com/kubernetes/kubernetes/pull/121240), [@HirazawaUi](https://github.com/HirazawaUi))

- Fixed a bug that unintentionally overrides custom Accept headers in http (live-/readiness)-probes if the header is in lowercase. ([#114606](https://github.com/kubernetes/kubernetes/pull/114606), [@tuunit](https://github.com/tuunit))