DZone
This Zato how-to is about ensuring that only API clients with valid SSL/TLS certificates, including expected certificate fingerprints or other metadata, can invoke selected REST endpoints. In this way, we are making access to the endpoints secure and, at the same time, we can guard against a class of faults related to the Certificate Authority infrastructure.
Overview
Given that in front of all Zato servers in a cluster is a load-balancer, it is the load-balancer that accepts API client connections.
Source: DZone