If an error occurs during the routing, such as when the selected route has a transmission problem that corrupts the frame, an Internet Control Message Protocol (ICMP) packet is delivered to the host, informing the host of the problem.

• 如果在寻找路径的过程中发生错误，比如当一条选中的路径发生传输硬件故障从而破坏了帧时，一个互联网控制信息协议（ICMP）数据包就送达发出此帧的主机，通知该机此帧数据发生了问题。