Slow TcpClient DNS resolution

Client.Program.cs

using System.Net.Sockets;

int iterations = 10;
long totalElapsed = 0;
for (int i = 0; i < iterations; i++)
{
    var tcpClient = new TcpClient();
    var sw = System.Diagnostics.Stopwatch.StartNew();
    await tcpClient.ConnectAsync("localhost", 6510);
    long elapsed = sw.ElapsedMilliseconds;
    totalElapsed += elapsed;
    Console.WriteLine("Connected");
    tcpClient.Dispose();
}
Console.WriteLine($"Average {totalElapsed / iterations}");

Server.Program.cs

using System.Net;
using System.Net.Sockets;

var endPoint = new IPEndPoint(IPAddress.Any, 6510);
var listener = new TcpListener(endPoint);
listener.Start();
_ = Task.Run(() => ListenAsync(listener));


Console.WriteLine("Listening");
Console.ReadLine();

async Task ListenAsync(TcpListener listener)
{
    while (true)
    {
        Socket clientSocket = await listener.AcceptSocketAsync();
    }
}