You can modify the port in file /etc/services. you can modify your port here but make sure that this port is open through the firewall for both filer source and destination.
sm-sync-block 10567/tcp # Snapmirror Sync Block Data
sm-sync-trans 10568/tcp # Snapmirror Sync Transaction Data
sm-sync-ctrl 10569/tcp # Snapmirror Sync Control Data
nbu-nearstore 10571/tcp # NetBackup - Nearstore
|sm-ics-test||10670/tcp # INTERNAL USE: Snapmirror Multipath|