ping

Additional Notes

ping sends ICMP echo requests to a host and waits for replies. It is a basic tool for checking whether a host is reachable and roughly how much latency exists.

A failed ping does not always mean the host is down. Firewalls, routers, cloud providers, or local policy may block ICMP.

Syntax

ping [options] host

Parameters

• options: Flags that change how ping behaves.
• host: Hostname, IP address, URL, or network target.

Common Options

• -c N: Send N packets, then stop.
• -i SECONDS: Wait between packets.
• -4: Use IPv4.
• -6: Use IPv6.
• -W SECONDS: Wait time for a reply.
• -s SIZE: Set packet payload size.
• -q: Quiet summary output.

Examples

ping example.com

Ping a domain continuously until stopped.

ping -c 4 8.8.8.8

Send four packets to an IP address.

ping -4 example.com

Force IPv4.

ping -6 example.com

Force IPv6.

ping -c 3 -W 2 gateway.local

Send three packets with a two-second reply timeout.

Reading Output

• time=: Round-trip latency.
• ttl=: Time-to-live value from the reply.
• Packet loss: Percentage of packets with no reply.
• Summary min/avg/max: Latency statistics.

Practical Notes

• First test your gateway, then a public IP, then DNS names.
• If IP ping works but domain ping fails, suspect DNS.
• If ping fails but a web service works, ICMP may be blocked.
• Use traceroute to inspect the path when reachability is unclear.