用C#写了一个WEB，功能：用斑马打印机（105SL）打印条码。代码如下：
public static    void   Print_PENO(string ZPLString, string ipAddress)
        {//ZPLString是机器码，ipAddress是打印机IP
            int port = 9100;
           
            try
            {
                // Open connection
                System.Net.Sockets.TcpClient client = new System.Net.Sockets.TcpClient();
                client.Connect(ipAddress, port);
                // Write ZPL String to connection
                System.IO.StreamWriter writer = new System.IO.StreamWriter(client.GetStream());
                writer.Write(ZPLString);
                writer.Flush();
                // Close Connection
                writer.Close();
                client.Close();             
            }
            catch (Exception ex)
            {
                throw ex;            
            }
        }
调用后，执行到ter.Flush();出错：Unable to write data to the transport connection: 遠端主機已強制關閉一個現存的連線。

你不是把串口的指令发给以太网口了吧

居然是IP衝突。
怎麼找都找不到原因，一氣之下，把列印機關了，怎么还能PING的通。