martensit

using System.Net;

string postData = "post string";
byte[] data = Encoding.ASCII.GetBytes(postData);
HttpWebRequest req = (HttpWebRequest)WebRequest.Create("http://122.233.155.155:80");
req.Method = "POST";
req.ContentLength = postData.Length;
req.Timeout = 10000;
using (Stream stream = req.GetRequestStream()) stream.Write(data, 0, data.Length);
using (HttpWebResponse response = (HttpWebResponse)req.GetResponse())
{
    var buffer = new byte[response.ContentLength];
    response.GetResponseStream().Read(buffer, 0, buffer.Length);
    Console.WriteLine(buffer.Length);
}

Или же PPPOE подключение будет поднимать сам ONU(ONT)?

netsh interface ipv4 show interfaces "RT" | findstr Состояние

string[] dirs = Directory.GetFiles(path).Where(file => !file.EndsWith(".exe"));

string[] files = Directory.GetFiles(dir);
string[] notExec = files.Where(f => Path.GetExtension(f) != ".exe").ToArray();