SqlConnection cn1=new SqlConnection("Integrated Security=SSPI;Initial Catalog=TestDB;Data Source=STORAGE;");
cn1.Open();
Show();
			
SqlConnection cn2=new SqlConnection("Integrated Security=SSPI;Initial Catalog=TestDB;Data Source=STORAGE;Persist Security Info=False;");
cn2.Open();
Show();
			
cn1.Close();
Show();

private static void Show()
{
  Type sc=typeof(System.Data.SqlClient.SqlConnection);
  Type pm=Assembly.GetAssembly(sc).GetType("System.Data.SqlClient.SqlConnectionPoolManager");
   // SqlConnectionPoolManager 
  object cm=pm.InvokeMember(null, BindingFlags.CreateInstance, null, null, new object[0]);
   // PoolManager 
  object mm=pm.InvokeMember("_manager", BindingFlags.GetField | BindingFlags.NonPublic | BindingFlags.Static, null, pm, new object[0]);

  Hashtable map1=(Hashtable)mm.GetType().InvokeMember("_map", BindingFlags.GetField | BindingFlags.NonPublic | BindingFlags.Instance, null, mm, new object[0]);
  Hashtable map2=(Hashtable)mm.GetType().InvokeMember("_mapSSPI", BindingFlags.GetField | BindingFlags.NonPublic | BindingFlags.Instance, null, mm, new object[0]);
   // остановись здесь и посмотри в debuger'e содержимое таблиц :) 
}