Ping is a network administration utility used to test the reachability of a host on an Internet Protocol network. This command is used for troubleshooting the accessibility of devices between two endpoints. This utility uses a series of Internet Control Message Protocol (ICMP) echo messages to determine whether a remote host is active or inactive, the round-trip delay in communicating with the host, packet loss. The ping command first sends an echo request packet to an address, then waits for a reply. The ping is successful only if the echo request gets to the destination, and the destination gets an echo reply back to the source within a predetermined time called a timeout. Here are some related articles: Ping request could not find the host: Verify if the name is entered correctly, what is transit failed, general failure, request timed out and destination host unreachable, why can’t I ping an EC2 instance Public IP Address, and how to resolve request timed out when pinging and how to create a Firewall rule.
Here is an example, I have an Linux EC2 Instance say, private IP is 10.10.10.10, public IP is 54.54.54.54.Note: Inside the instance, I could successfully ping its private IP(10.x0.10.x0) and localhost. However, I cannot ping its public IP(54.xxx.54.x4).
Solution: Why can’t I ping an EC2 instance public IP from inside of the instance itself? When encountering this issue, resolve it by adding the following rule to the instance’s security group.
Simply added the EIP of the instance to allow echo reply and request to the Public IP
I hope you found this blog post helpful. If you have any questions, please let me know in the comment session.