ping命令在同一网段中数据包的什么变什么不变？

如题目中说的：ping命令在同一网段中数据包的什么变什么不变？希望详细的说一下原因，谢谢

变化部分见加粗：

Pinging 192.168.4.1 with 32 bytes of data:

Reply from 192.168.4.1: bytes=32 time<1ms TTL=255 ----可能整条条数据会没有，提示Request timed out. ，表示无法ping 通
Reply from 192.168.4.1: bytes=32 time<1ms TTL=255
Reply from 192.168.4.1: bytes=32 time<1ms TTL=255
Reply from 192.168.4.1: bytes=32 time<1ms TTL=255

Ping statistics for 192.168.4.1:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 0ms, Average = 0ms

其他：

Sent = 4, Received = 4, Lost = 0 表示发送的包数目，对方收到的包数目，没收到的包数据