icmp的报文，Destination Host Unreachable的意思如下：

 

The error message "Destination Host Unreachable " tells that the ping request from our computer cannot find the route to the destination IP address(destination network device). It means the Packet send from your computer reached the destination network successfully but it failed to find the destination host. Destination host can be any networking device (with one unique IP address) in the destination network. One major possibility for this error is there is no route for the packet send from your computer to destination host. If there is no route available, it is impossible to find the destination host and your computer will get an error message "Destination host unreachable" instead of replies. So the issue can be due to faulty routing table. If the destination host is down at the time the packet send, it may result destination host unreachable error message. So here I conclude all possible reasons for Destination host unreachable error message with possible troubleshooting steps.