The requested vessel with name ISTROS and MMSI:0 and IMO:7211490 is temporary not in our database.
Perhaps you mean one of the following ships:

Vessel name IMO MMSI In range Destination Last report
ISTROS N/A 264162458 CONSTANTA Jan 16, 2018 16:42 UTC

Also, you may try to find the vessel in our comprehensive Vessels Database or track this ship on the map.