[C#] Get Available Port.cs

GetAvailablePort(8080);

[C#] GetAvailablePort(int startingPort).cs

using System.Net.NetworkInformation;

// ..

// from https://stackoverflow.com/a/45384984
public static int GetAvailablePort(int startingPort)
{
    var portArray = new List<int>();

    var properties = IPGlobalProperties.GetIPGlobalProperties();

    // Ignore active connections
    var connections = properties.GetActiveTcpConnections();
    portArray.AddRange(from n in connections
        where n.LocalEndPoint.Port >= startingPort
        select n.LocalEndPoint.Port);

    // Ignore active tcp listners
    var endPoints = properties.GetActiveTcpListeners();
    portArray.AddRange(from n in endPoints
        where n.Port >= startingPort
        select n.Port);

    // Ignore active udp listeners
    endPoints = properties.GetActiveUdpListeners();
    portArray.AddRange(from n in endPoints
        where n.Port >= startingPort
        select n.Port);

    portArray.Sort();

    for (var i = startingPort; i < UInt16.MaxValue; i++)
        if (!portArray.Contains(i))
            return i;

    return 0;
}