ต้องการเขียน log file การ Login ลงเครื่อง server ตามหมายเลข IP ไม่ทราบทำอย่างไรคะ

Private Sub btnLogin_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btnLogin.Click
        Dim con As New SqlConnection
        Dim cmd As New SqlCommand
        Dim rd As SqlDataReader
        con.ConnectionString = "Data Source=localhost; Initial Catalog = MMS; Integrated Security= true"
        '  con.ConnectionString = ("user id = sa;data source = 192.168.5.24 ; persist security info = True;initial catalog = MMS ;password = ttcadmin")
        cmd.Connection = con
        con.Open()
        cmd.CommandText = "Select Emp_id, Password from Employee where Emp_id  ='" & txtUsername.Text & "'and Password = '" & txtPassword.Text & "'"

        rd = cmd.ExecuteReader

        If rd.HasRows Then
            MessageBox.Show("Welcome to Machine Mantenance System.", "Login", MessageBoxButtons.OK, MessageBoxIcon.Information)
            frmMain.user_idLogin = txtUsername.Text
            frmMain.Show()
            Me.Hide()

            Dim sw As StreamWriter = New StreamWriter("d://log.txt", True)
            sw.WriteLine(Me.txtUsername.Text & ";" & Date.Now.ToString("dd/MM/yyyy"))
            sw.Close()

        ElseIf txtUsername.Text = "" Or txtPassword.Text = "" Then
            MessageBox.Show("Please enter username and password.", "Login", MessageBoxButtons.OK, MessageBoxIcon.Error)
        Else
            MessageBox.Show("Please enter username and password are correct.", "Login", MessageBoxButtons.OK, MessageBoxIcon.Error)

        End If
        con.Close()

        frmMachineRecord.EmpID = txtUsername.Text
    End Sub