There are 2 main properties that Ionic compounds share:
1) High melting and boiling points. - Ionic bonds are extremely strong. So therefore, lots heat energy is needed to break them down. So ionic compounds have high melting and boiling points.
2) Conductive when liquid- Ions are charged particles, but ionic compounds can only conduct electricity if their ions are free to move. They are not free to move in a solid state, however they are free to move when the compound has been melted or dissolved in a liquid.
Hope this helps! :)