We have a clustered index setup (two indexers) on 7.1.1 and 3 search heads (unclustered). What is the recommended method to disable SSL and TLS1.0 globally on all forwarders, indexers and search heads with this setup ?
The easiest way to do so is to have a deployment server. Depending on the amount of UFs you have on your environment you could use the Cluster Master as Deployment Server and use it to deploy the config to everyone.
Please make remember changes to the two clustered indexers must only be created via the cluster master.
More info here about the deployment server: https://docs.splunk.com/Documentation/Splunk/7.3.1/Updating/Aboutdeploymentserver
(note the bottom part about the indexer cluster)