Ping in libp2p
The libp2p ping protocol is a simple liveness check that peers can use to test the connectivity and performance between two peers. The libp2p ping protocol is different from the ping command line utility (ICMP ping), as it requires an already established libp2p connection.
ICMP Ping is a network utility that uses ICMP packets to check the connectivity and latency between two networked devices. It is typically used to check the reachability of a host on an IP network and to measure the round-trip time for messages sent from the originating host to a destination host.
A peer opens a new stream on an existing libp2p connection and sends a ping request with a random 32 byte payload. The receiver echoes these 32 bytes back on the same stream. By measuring the time between the request and response, the initiator can calculate the round-trip time of the underlying libp2p connection. The stream can be reused for future pings from the initiator.
The ping protocol ID is
Kubo exposes a command line interface to ping other peers, which uses the libp2p ping protocol.
ipfs ping /ipfs/QmYwAPJzv5CZsnA625s3Xf2nemtYgPpHdWEz79ojWnPbdG/ping
PING /ipfs/QmYwAPJzv5CZsnA625s3Xf2nemtYgPpHdWEz79ojWnPbdG/ping (QmYwAPJzv5CZsnA625s3Xf2nemtYgPpHdWEz79ojWnPbdG)
32 bytes from QmYwAPJzv5CZsnA625s3Xf2nemtYgPpHdWEz79ojWnPbdG: time=11.34ms