Why can ping fail while traceroute can

ping It's going ICMP agreement .tracert I was shocked to follow the route .. The two commands are different .
If the server is not enabled ICMP The protocol or firewall is disabled ICMP, And I didn't do address mapping ICMP Mapping , Will result in ping no ..
tracertoute The routing switch needs to be enabled ip Tracking is the only way .

Description the target machine refused to respond ICMP Of echo nothing more .
ping When , Is to send one icmp Of echo, The target machine corresponds to one reply. Then I think it's OK .
traceroute Also hair icmp echo, however , hold TTL from 1 Start , Gradually increase . Nodes on the path , Receive a TTL by 0 Of ICMP When , An error message will be returned . In this way , Learn about the nodes on the path .
If a target machine , Do not respond to icmp echo, But still responded icmp echo in TTL by 0 The situation of , This is your performance .

ping And traceroute All use icmp agreement , But its working principle and ICMP The definitions of type fields in are different ：
about ping, It's a echo request package , The type is 8 0, When ping The person receiving the relevant icmp When the package , According to the actual situation , Logic is , Just send it back reply 0 0, Logical not , Then send some other information according to the specific situation , To sum up , Is to see whether the purpose can be timely icmp reply The packet is sent back to the source , When a node on the path puts reply Give it to deny It fell off , I'm sure ping It doesn't work , For example, it will be time out,
about traceroute, The essence can be understood as hop by hop Of ping, But this ping And the above ping Dissimilarity , This ping And our ping Different commands ,traceroute After the package is sent out , Each site will send back one The type code is 11 0 Of icmp Pack it back , To the end point , Just send back a code as 3 3 Of icmp Package back to source
therefore , If at some point in the path （ Router ） On , Restricted types 11 Of ICMP message （ICMP Packets are the most common limitation of firewalls ）, Your situation will appear .