You execute the ping command from a host, but the router does not have a path to its destination.
Which of the following ICMP message types will a client receive from the router?

A.
ICMP redirect

B.
ICMP time exceeded

C.
ICMP destination unreachable

D.
ICMP echo-reply

Explanation:
When a router receives a ping packet and has no route to the destination in its routing table, it will respond to
the client with an ICMP destination-unreachable message. Internet Control Message Protocol (ICMP) is a Layer
3 protocol used to test the connectivity between hosts in a network. There are six types of unreachable
destination message:
1. Network unreachable
2. Host unreachable
3. Protocol unreachable
4. Port unreachable
5. Fragmentation needed and Don’t Fragment (DF) bit set
6. Source route failed
An ICMP redirect message would not be received. This type of response is received when the router is
configured to direct clients to a different router for better routing.
An ICMP time-exceeded message would not be received. This type of response occurs when the router
successfully sent the packet but did not receive an answer within the allotted time; in other words, the time-tolive of the ICMP packet has been exceeded.
An ICMP echo-reply message would not be received. This would be the response received if the destination
received the ping command and responded successfully.
Objective:
Routing Fundamentals
Sub-Objective:
Troubleshoot basic Layer 3 end-to-end connectivity issues

Cisco > Internetworking Technology Handbook > Internet Protocols (IP) > Internet Control Message Protocol
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