[Solved]-Override default highlighting on hover in networkgraph-Highcharts

Overwrite the default setState method from networkgraph Point class prototype and use your iterateBack function in mouse over event.

(function(H) {
    H.seriesTypes.networkgraph.prototype.pointClass.prototype.setState = function() {
        H.Point.prototype.setState.apply(this, arguments);
    }
}(Highcharts));

Live demo: https://jsfiddle.net/BlackLabel/ua72mrqp/

Docs: https://www.highcharts.com/docs/extending-highcharts/extending-highcharts