DUPLICATE AND DAMAGED PACKETS
- The ping utility will report duplicate and damaged packets. Duplicate packets should never occur when pinging a unicast address, and seem to be caused by inappropriate link-level retransmissions. Duplicates may occur in many
- situations and are rarely (if ever) a good sign, although the presence of low levels of duplicates may not always be cause for alarm. Duplicates are expected when pinging a broadcast or multicast address, since they are not really
duplicates but replies from different hosts to the same request.
Damaged packets are obviously serious cause for alarm and often indicate broken hardware somewhere in the ping packet’s path (in the network or in the hosts).
大概意思：重复和损坏的数据包
- Ping将报告重复和损坏的数据包。当使用单播地址时，不应该出现重复的数据包，而且出现重复数据包似乎时是由不适当的链路重传引起的。
- 重复可能在很多情况下发生，而且很少（如果有的话）是一个好的现象，尽管低水平的重复现象不总会造成警报。
当在ping一个广播或多播地址时会出现重复包，因为他们不是真正的重复，而是来自不同主机对相同请求的是响应。
损坏包显然时可以引起严重的恐慌，通常指出在ping包的路径下哪部分硬件坏掉了（网络或主机）。
Android 平台ping 对方ip返回 +3 duplicates （重复回应包）
原文：https://www.cnblogs.com/skyeblogs/p/9268390.html
