With Dynamic Discovery, each time the initiator contacts a specified iSCSI server, it sends the SendTargets request to the server. The server responds by supplying a list of available targets to the initiator.
When you set up Dynamic Discovery, you can only add a new iSCSI server. You cannot change the IP address, DNS name, or port number of an existing iSCSI server. To make changes, delete the existing server and add a new one.