IP & Network
ICMP ping: latency, TTL and packet loss.
Ping measures round-trip with ICMP echo. The measurement is from the IPTOOL server, not your PC, so it will not match a local ping.
Loss or high RTT can be congestion, distance, or the target filtering ICMP. Many hosts drop ping; that does not mean the site is down.
RTT follows distance and peering. 1–10 ms in the same city, hundreds of ms between continents is normal. TTL drops at each hop.
The target may drop ICMP. If HTTP still returns 200, the service is up.
If the target has AAAA, IPv6 echo is used. Dual-stack choice depends on the form.
To curb abuse. ICMP is a resource; only a few packets go out per window.
Addresses like 1.1.1.1 hit the nearest node; a path change changes RTT.
No. This is Linux ICMP ping from this server’s IP.