Yes they can be shared.  However you cannot use FSN or LACP (which you often want to for NAS HA) on a port which is being used for iSCSI.   See [URL] page 15.
hi,   We only have 4-5 servers in our enviroment. So thruput and performance is not the issue. We need to know if we can use the same port for iscsi and as a NAS server interface on unity 350? any document supporting why or why not will be really great!!   Thanks a ton, Vivek 
nas+iscsi on same Unity port ?