Segment health check

Segment-based health-check is used to verify health of single instance in transparent service chain. User is expected to create service-health-check object with type as segment-based and attach it to either left or right interface of service-instance whose health has to be verfied. If service-health-check object is attached to left interface of service-instance, then health-check packet will be injected to left interface. When packet comes out of right interface a reply packet is injected on right interface. If health-check requests fail continuously for user configured retries, then service-instance is considered unhealthy and the service vlan routes of left and right interface are removed.