you are mixing 2 different things
The snapmirror list-destinations command displays information including the destination endpoints, the relationship status, and transfer progress, for SnapMirror relationships whose source endpoints are in the current Vserver if you are in a Vserver context, or the current cluster if you are in a cluster context.
[-type <snapmirrorType>] - Relationship TypeSelects SnapMirror relationships that have a matching relationship type. Possible values are:
snapmirror list-destinations comand output shows you information about snapmirror relationships on the source
and the field type in the output shows you a type of the relationship itself, NOT the type of the volumes included in the relationship
The volume show command displays information about volumes. The command output depends on the parameter or parameters specified with the command. If no parameters are specified, the command displays the following information about all volumes:
- Type (RW for read-write or DP for data-protection)
volume show command shows you information about the volume itself.
where field type means a type of the volume, NOT a type of the relatioship.
With a snapmirror relatioship you have always 2 volumes included:
one volume is a source volume, which type is RW and another is destination volume which type is DP
between those 2 volumes is a snapmirror relationship which type depends of the configuration may be DP or XDP