thinQmaster Virtual testing partner Adaptive practice exams that find your weak spots and drill them. Every answer explained. From $69
Enroll

thinQmaster

Find your exam

Five questions free, before you decide.

Step 1 · choose a vendor

In one of our camps? Your practice exams come with the tuition — they are on your study page already.

Networking Fundamentals · Foundational

ICMP Echo Reply

ICMP type 0 message returned in response to an echo request, confirming reachability and providing round-trip time.

Definition

Ping displays each reply with its size, round-trip time and TTL. ICMPv6 Echo Reply is type 129.

Example

"Reply from 8.8.8.8: bytes=32 time=14ms TTL=117" reports an echo reply.

Exam tip

A reply that says "Destination host unreachable" is not an echo reply; it comes from a router or the local host.

Related terms