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C# .NET print to default Printer

I need to update this program to print to whichever printer the user has selected as their default printer. Currently I'm using the IP address of the printer but it will be different depending on the pc.
Socket clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
clientSocket.NoDelay = true;
PrinterSettings settings = new PrinterSettings();
IPAddress ip = IPAddress.Parse("ipaddress");
IPEndPoint ipep = new IPEndPoint(ip, 9100);
clientSocket.Connect(ipep);
try {
clientSocket.Send(output.ToArray());
} catch (Exception) {}

Communicate over Internet Client/Server

I know there are many threads about this theme, but i can not make it. I want to send a letter or a number over the Internet(not Local!). I have tried it with Ipv6 and Ip4 but both did not work. If you can pls in C# or Java :c Here are some code samples:
//Server
Socket sock = new Socket(AddressFamily.InterNetworkV6, SocketType.Stream, ProtocolType.Tcp);
sock.SetSocketOption(SocketOptionLevel.IPv6, (SocketOptionName)27, 0);
sock.Bind(new IPEndPoint(IPAddress.IPv6Any, 5005));
sock.Listen(4);
Socket client = sock.Accept();
Console.WriteLine("Works!");
Console.ReadKey();
//Client
string ip;
ip = Console.ReadLine();
IPAddress ipad = IPAddress.Parse(ip);
Socket sock = new Socket(AddressFamily.InterNetworkV6,
SocketType.Stream,
ProtocolType.Tcp);
Console.WriteLine("try to "+ipad,
ipad);
sock.Connect(ipad, 5005);
Console.WriteLine("yesssssss");
Console.ReadKey();

How can I add SSL encryption to available TCP/IP socket

I am going to upgrade a system which used TCP connection without SSL. I want to add SSL encryption to the current connection without changing much in code. This is what there was previously in the code.
IPAddress ipAddress = IPAddress.Parse(IpAddress);
IPEndPoint remoteEP = new IPEndPoint(ipAddress, Port);
// Create a TCP/IP socket.
var client = new Socket(AddressFamily.InterNetwork,
SocketType.Stream, ProtocolType.Tcp);
client.BeginConnect(remoteEP,new AsyncCallback(ConnectCallback), client);
What I tried is this,
IPAddress ipAddress = IPAddress.Parse(IpAddress);
IPEndPoint remoteEP = new IPEndPoint(ipAddress, Port);
// Create a TCP/IP socket.
var client = new Socket(AddressFamily.InterNetwork,
SocketType.Stream, ProtocolType.Tcp);
client.BeginConnect(remoteEP, new AsyncCallback(ConnectCallback), client);
while (!client.Connected) { }
NetworkStream stream = new NetworkStream(client);
SslStream ssl = new SslStream(stream, false, ValidateServerCertificate);
But this is not doing what I need. At least ValidateServerCertificate delegate is not called.
What's wrong with my code?
IMPORTANT
I cannot remove this socket named client during the change because it will affect lot of other codes.

Sending and Receiving UDP packets

The following code sends a packet on port 15000:
int port = 15000;
UdpClient udp = new UdpClient();
//udp.EnableBroadcast = true; //This was suggested in a now deleted answer
IPEndPoint groupEP = new IPEndPoint(IPAddress.Broadcast, port);
string str4 = "I want to receive this!";
byte[] sendBytes4 = Encoding.ASCII.GetBytes(str4);
udp.Send(sendBytes4, sendBytes4.Length, groupEP);
udp.Close();
However, it's kind of useless if I can't then receive it on another computer. All I need is to send a command to another computer on the LAN, and for it to receive it and do something.
Without using a Pcap library, is there any way I can accomplish this? The computer my program is communicating with is Windows XP 32-bit, and the sending computer is Windows 7 64-bit, if it makes a difference. I've looked into various net send commands, but I can't figure them out.
I also have access to the computer (the XP one)'s local IP, by being able to physically type 'ipconfig' on it.
EDIT: Here's the Receive function I'm using, copied from somewhere:
public void ReceiveBroadcast(int port)
{
Debug.WriteLine("Trying to receive...");
UdpClient client = null;
try
{
client = new UdpClient(port);
}
catch (Exception ex)
{
Debug.WriteLine(ex.Message);
}
IPEndPoint server = new IPEndPoint(IPAddress.Broadcast, port);
byte[] packet = client.Receive(ref server);
Debug.WriteLine(Encoding.ASCII.GetString(packet));
}
I'm calling ReceiveBroadcast(15000) but there's no output at all.

Here is the simple version of Server and Client to send/receive UDP packets
Server
IPEndPoint ServerEndPoint= new IPEndPoint(IPAddress.Any,9050);
Socket WinSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
WinSocket.Bind(ServerEndPoint);
Console.Write("Waiting for client");
IPEndPoint sender = new IPEndPoint(IPAddress.Any, 0)
EndPoint Remote = (EndPoint)(sender);
int recv = WinSocket.ReceiveFrom(data, ref Remote);
Console.WriteLine("Message received from {0}:", Remote.ToString());
Console.WriteLine(Encoding.ASCII.GetString(data, 0, recv));
Client
IPEndPoint RemoteEndPoint= new IPEndPoint(
IPAddress.Parse("ServerHostName"), 9050);
Socket server = new Socket(AddressFamily.InterNetwork,
SocketType.Dgram, ProtocolType.Udp);
string welcome = "Hello, are you there?";
data = Encoding.ASCII.GetBytes(welcome);
server.SendTo(data, data.Length, SocketFlags.None, RemoteEndPoint);

udp can not receive any data

Here is my code
Socket sck = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
sck.Bind(new IPEndPoint(IPAddress.Any, 0));
// Broadcast to find server
string msg = "Imlookingforaserver:" + udp_listen_port;
byte[] sendBytes4 = Encoding.ASCII.GetBytes(msg);
IPEndPoint groupEP = new IPEndPoint(IPAddress.Parse("255.255.255.255"), server_port);
sck.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.Broadcast, 1);
sck.SendTo(sendBytes4, groupEP);
//Wait response from server
Socket sck2 = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
sck2.Bind(new IPEndPoint(IPAddress.Any, udp_listen_port));
byte[] buffer = new byte[128];
EndPoint remoteEndPoint = new IPEndPoint(IPAddress.Any, udp_listen_port);
sck2.ReceiveFrom(buffer, ref remoteEndPoint); //<<< I never pass this line
I use above code to try find a server. First I broadcast a message and then I wait for a response from the server.
A test I made with the server written in C++ and running in Windows Vista, client written in C# and run on the same machine with server.
Problem is: The server can receive message which client broadcast, but client can not receive anything from server.
I try to write a client with C++ and it work like a charm, I think my problem is in C# client.

I would start listening on that port before you broadcast. You're using UDP which is connectionless so you could be missing your packet.
Socket sck = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
sck.Bind(new IPEndPoint(IPAddress.Any, 0));
//Wait response from server
Socket sck2 = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
sck2.Bind(new IPEndPoint(IPAddress.Any, udp_listen_port));
byte[] buffer = new byte[128];
EndPoint remoteEndPoint = new IPEndPoint(IPAddress.Any, udp_listen_port);
// Broadcast to find server
string msg = "Imlookingforaserver:" + udp_listen_port;
byte[] sendBytes4 = Encoding.ASCII.GetBytes(msg);
IPEndPoint groupEP = new IPEndPoint(IPAddress.Parse("255.255.255.255"), server_port);
sck.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.Broadcast, 1);
sck.SendTo(sendBytes4, groupEP);
sck2.ReceiveFrom(buffer, ref remoteEndPoint);