Explanation/Reference:
References: https://www.emc.com/collateral/TechnicalDocument/docu69316.pdf (p.11)

Explanation
The following requirements are related to the Integrated ESRS implementation only:
If your ESRS implementation will include a proxy server to connect to the Internet, you must indicate this when you configure the ESRS feature.
If your ESRS implementation will include a Policy Manager for more control over remote access to your storage system, you must indicate this when you configure the ESRS feature.
If your ESRS implementation will include a proxy server for your storage system to connect to a Policy Manager, you must indicate this when you configure the ESRS feature References: https://www.emc.com/collateral/TechnicalDocument/docu69327.pdf (page 12)

Explanation
Attaching a snapshot is only applicable for block snapshots, and makes the snapshot available for host IO. A host must have Snapshot access or LUN and Snapshot access configured in order to access the snapshot. When a snapshot is attached, Unisphere provides the option to create a copy of the snapshot in case the administrator wants to preserve the current snapshot view for future use.

References:
https://www.dellemc.com/sr-me/documentation/unity-family/unity-p-config-luns/02-configuring-lun-move.htm

Explanation/Reference:
Only one FC port can be configured and used for synchronous replication. Once an FC port is assigned, it will continue to act as the synchronous replication port and can never be changed. To determine the FC port used for synchronous replication, in the CLI console, run the command /remote/sys show -detail. Port information, similar to the following example, will appear in the output:
Synchronous FC ports = spb_fc4, spa_fc4
References: https://www.emc.com/en-us/documentation/unity-family/unity-p-replication-config/03-unity-rep- br-considerations-syncrep.htm