Monitor types
Ping monitors (ICMP)
Measure reachability, latency and packet loss of a host with ICMP echo requests, with an automatic TCP fallback when ping is blocked.
- API type
ping- You enter
- Hostname or IP
- Runs at most every
- Plan minimum
- Needs
- None
FastPing resolves the host (IPv4 preferred) and sends 3 ICMP echo requests, 0.3 seconds apart, waiting up to 2 seconds for each reply. The response time is the average round trip.
- Up: all 3 replies arrived.
- Warning: some replies were lost. The message shows the loss, for example
icmp avg 24.31 ms, loss 33%. - Down: no reply at all, confirmed by the usual re-check.
Many hosts and cloud firewalls block ICMP. When no ICMP reply arrives at all, FastPing measures TCP connections to port 443, then port 80, before giving up. If one of them answers, the monitor stays up and the message shows the method used, for example tcp/443 avg 18 ms, loss 0%.
Ping tells you that a machine is reachable and how good the network path is, not that a service works. Pair it with a check of the service itself: a website monitor for web servers, a TCP port monitor for databases or SSH, a game server monitor for game hosts. When the service check fails but ping is fine, the problem is the application, not the network.
Because a single lost packet out of 3 already causes a warning, ping monitors on lossy links (Wi-Fi bridges, congested home connections) can warn often. A TCP port monitor is calmer in that situation.
| Message | What it means | What to do |
|---|---|---|
100% packet loss | No ICMP reply, and neither port 443 nor port 80 accepted a connection. | Check that the host is running and that its firewall allows ICMP echo from FastPing, or monitor a port the host serves. |
Could not resolve host.example.com. | The hostname has no DNS address. | Check the DNS records. |
Private or reserved addresses are not allowed. | The address is in a private or reserved range (10.0.0.0/8, 192.168.0.0/16, 100.64.0.0/10…). | Use the host's public address. |
Run the Ping test or the Traceroute to see the same measurement and the network path from our server.