How to Syncronize artifcats between geographically distributed Nexus Servers

Hi , we have a distributed nexus environment where we would like to have a Master Nexus Server which will be used to Publish both release and snapshots and there will be other servers geographically distributed which will be allowed to publish Snapshots, what is the best way so that once Master Server is publishing some artifacts they are made available on respective servers in different locations and also if needed artifacts can be published from salves to Master . we are in the process of setting up new Nexus 3 Servers and we do have working environments using Nexus 3 proxy repository which are proxied from Nexus 2 Pro servers.