We would need to support the Client-IP based session affinity by load-balancing, as defined below:

From https://kubernetes.io/docs/concepts/services-networking/service/ :

Any traffic bound for the Service’s IP:Port is proxied to an appropriate backend without the clients knowing anything about Kubernetes or Services or Pods. Client-IP based session affinity can be selected by setting service.spec.sessionAffinity to “ClientIP” (the default is “None”), and you can set the max session sticky time by setting the field service.spec.sessionAffinityConfig.clientIP.timeoutSeconds if you have already set service.spec.sessionAffinity to “ClientIP” (the default is “10800”)

That means:

• affinity disabled by default
• ability to enable affinity per LB NAT rule
• ability to specify timeout for the affinity