The Origin of the ping Command - A Network Tool Born from Submarine Sonar

ping - The Command Born from Submarine Sonar

The first command you run when troubleshooting a network: ping. Its name comes from the "ping" sound made by submarine sonar (acoustic depth finders). Just as sonar emits a sound wave and measures distance by timing the reflected wave's return, ping sends a packet and measures network reachability and latency by timing the response.

The Birth of ping - Mike Muuss's Overnight Work in 1983

ping was written in December 1983 by Mike Muuss, an engineer at the US Army Ballistic Research Laboratory (BRL). While investigating a network outage, Muuss realized there was "no simple tool to check whether packets are reaching the destination" and implemented ping in a single night.

As Muuss later recounted, the name was inspired by submarine sonar. The operation of "sending a packet and waiting for the reflection" resembled sonar, so he intuitively named it "ping." Some sources claim it stands for "Packet InterNet Groper," but Muuss dismissed this as a backronym (a retroactively constructed acronym).

ICMP - The Protocol Behind ping

ping uses ICMP (Internet Control Message Protocol) Echo Request and Echo Reply messages. Unlike TCP or UDP, ICMP is designed not for data transfer but for network control and diagnostics.

The operation of ping is straightforward:

1. The source sends an ICMP Echo Request packet to the destination
2. The destination receives the packet and sends back an ICMP Echo Reply
3. The source measures the round-trip time (RTT)

This RTT is the fundamental metric for network latency that you can observe on IP Check-san. A ping from Tokyo to the US West Coast typically takes about 100-120 ms, and to Europe about 200-250 ms. Most of this latency is the physical time it takes light to travel through undersea cables.

What ping Can and Cannot Tell You

What It Can Tell You

• Reachability: Whether the destination host is reachable on the network
• RTT (round-trip latency): The time for a packet's round trip. Gives you a sense of the network "distance"
• Packet loss: The percentage of sent packets that received no response. A network quality indicator
• TTL (Time To Live): Allows estimation of how many routers the packet traversed. Subtracting the response TTL from the initial value (typically 64 or 128) gives the hop count

What It Cannot Tell You

• Bandwidth: ping sends only tiny packets (typically 64 bytes), so it cannot measure actual connection speed
• Service status: Even if ping gets a response, the web server or application may not be functioning properly
• Exact route: ping cannot show which routers the packet traversed (that's traceroute's job)

No Response Doesn't Necessarily Mean an Outage

When ping gets no response, the target isn't necessarily down. Many servers and firewalls intentionally block ICMP Echo Requests for security reasons.

• Windows Firewall: Configured to block ICMP Echo Requests by default
• Cloud providers: AWS Security Groups block ICMP unless explicitly allowed
• DDoS protection: Many networks rate-limit or block ICMP to prevent Ping Flood attacks using massive ICMP packets

If ping doesn't get through, try connecting to a specific port with curl or telnet, or use traceroute to see how far you can reach. Note that on public Wi-Fi networks, ICMP may be blocked entirely by the access point, so a failed ping doesn't always indicate a problem with the destination.

Commands Derived from ping

• traceroute / tracert: Displays the IP address and latency of each router along the path to the destination. Sends ICMP with incrementally increasing TTL values and records responses from each hop
• mtr (My Traceroute): Combines ping and traceroute. Continuously displays real-time latency and packet loss for each hop
• fping: Can send pings to multiple hosts simultaneously. Used for large-scale network monitoring
• hping: An advanced version that can send packets using any protocol including TCP, UDP, and ICMP. Also used for firewall testing and port scanning

What Happened to Mike Muuss

Mike Muuss, the creator of ping, was also known as the developer of BRL-CAD (an open-source 3D CAD system). Sadly, he passed away in a traffic accident in November 2000 at the age of 42.

The tool he wrote in a single night continues to be used daily by network engineers around the world more than 40 years later. Simple, reliable, and universal - it may be the ideal form of great software.