Chat between two different computers

I'm new to this Socket thing and I'm having trouble connecting two computers that are on the same network. When I run the client and the server on the same machine, it works ... but when I do this on different machines, the server does not identify the client connection.

I have read many questions and answers in various forums, watched videos on youtube, tried different solutions, already put the server IP in the client code and nothing ...

Could anyone tell me what I'm doing wrong? Thank you!

Server

import java.awt.List;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.ServerSocket;
import java.net.Socket;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextArea;
import javax.swing.UIManager;

public class Server extends JFrame implements ActionListener,Runnable  {
ServerSocket ss;
Socket s;
BufferedReader br;
BufferedWriter bw;
List list;
JButton btnExit;
JTextArea text;
JButton btnSend;

public Server() {
    setTitle("Secret Chat - Server");
    setSize(741,495);
    setLocation(300,0);
    getContentPane().setLayout(null);

    list = new List();
    list.setBounds(10, 48, 692, 275);
    getContentPane().add(list);

    btnExit = new JButton("Exit");
    btnExit.setBounds(613, 11, 89, 23);
    getContentPane().add(btnExit);
    btnExit.addActionListener(this);

    text = new JTextArea();
    text.setForeground(UIManager.getColor("ToggleButton.focus"));
    text.setLineWrap(true);
    text.setBounds(10, 338, 692, 74);
    getContentPane().add(text);

    btnSend = new JButton("Send");
    btnSend.setBounds(613, 423, 89, 23);
    getContentPane().add(btnSend);
    btnSend.addActionListener(this);

    setVisible(true);

    try
    {           
        list.add("Aguardando conexão de cliente...\n");

        ss = new ServerSocket(8375);

        s = ss.accept();
        br = new BufferedReader(new InputStreamReader(
                s.getInputStream()));
        bw = new BufferedWriter(new OutputStreamWriter(
                s.getOutputStream()));
        bw.write("... Você está conectado! ...");
        bw.newLine();
        bw.flush();
        Thread th;
        th = new Thread(this);
        th.start();
    }
    catch(Exception e)
    {
        //System.out.println("Exceção: " + e);
    }
}

 public static void main(String[] args) throws Exception
  {

     new Server();         

  }

@Override
public void run() {
    try
    {
        s.setSoTimeout(1);
    } catch(Exception e)
    {
        System.out.println("Exceção: " + e);
    }
    while (true)
    {
        try
        {
            list.add(br.readLine());
        }
        catch (Exception ex)
        {
            //System.out.println("Exceção: " + ex);
        }
    }

}

@Override
public void actionPerformed(ActionEvent e) {
     if (e.getSource().equals(btnExit))
         System.exit(0);
     else{try{
         list.add("Eu (Servidor): " + text.getText());
         bw.write("Patty " + text.getText());
         bw.newLine();
         bw.flush();
         text.setText("");
         } catch(Exception m){}
     }


}                    

}

Customer

import java.awt.List;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.Socket;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextArea;

    public class Client extends JFrame implements ActionListener,Runnable 
{
    List list;
    JTextArea text;
    JButton btnExit;
    JButton btnSend;
    Socket s;
    BufferedReader br;
    BufferedWriter bw;

    public Client() {
        setTitle("Secret Chat - Client");
        getContentPane().setLayout(null);

        list = new List();
        list.setBounds(10, 47, 692, 275);
        getContentPane().add(list);

        text = new JTextArea();
        text.setLineWrap(true);
        text.setBounds(10, 338, 692, 74);
        getContentPane().add(text);

        btnExit = new JButton("Exit");
        btnExit.setBounds(613, 11, 89, 23);
        btnExit.addActionListener(this);
        getContentPane().add(btnExit);

        btnSend = new JButton("Send");
        btnSend.setBounds(613, 423, 89, 23);
        btnSend.addActionListener(this);
        getContentPane().add(btnSend);

        setSize(741,495);
        setLocation(300,0);

        setVisible(true);

        try{
            /*Put the current IP address for current machine  
            if you didn't have an actual server and clients
            if you have an actual server and clients put the client IP address*/
            s = new Socket("10.1.XX.XXX",8375); // é aqui onde coloco o IP do servidor
            br = new BufferedReader(new InputStreamReader(s.getInputStream()));
            bw = new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
            bw.write("... Um usuário anônimo se conectou! ...");
            bw.newLine();
            bw.flush();
            Thread th;
            th = new Thread(this);
            th.start();

        } catch(Exception e){
            System.out.println(e);
        }
    }


    public static void main(String[] args) throws Exception
    {
        new Client();

    }

    @Override
    public void run() {
        try
        {
            s.setSoTimeout(2500);
        } catch(Exception e)
        {
            //System.out.println("Exceção: " + e);
        }

        while (true)
        {
            try
            {
                list.add(br.readLine());
            }
            catch (Exception e)
            {
                //System.out.println("Exceção: " + e);
            }
        }

    }

    @Override
    public void actionPerformed(ActionEvent e) {
         if (e.getSource().equals(btnExit))
             System.exit(0);
         else {
             try
             {
                 list.add("Eu (Cliente): " + text.getText());
                 bw.write("Anônimo: " + text.getText());
                 bw.newLine();
                 bw.flush();
                 text.setText("");
             } catch(Exception ex)
             {
                 //System.out.println("Exceção: " + ex);
             }
         }

    }                    
}