ping uses the ICMP protocol's mandatory ECHO_REQUEST datagram to elicit an ICMP ECHO_RESPONSE from a host or gateway. ECHO_REQUEST datagrams (``pings'') have an IP and ICMP header, followed by a struct timeval and then an arbitrary number of ``pad'' bytes used to fill out the packet.
ping6 is IPv6 version of ping, and can also send Node Information Queries (RFC4620). Intermediate hops may not be allowed, because IPv6 source routing was deprecated (RFC5095).
For every ECHO_REQUEST sent a period ``.''is printed,whilefor ever ECHO_REPLY received a backspace is printed.This provides a rapid display of how many packets are being dropped.If interval isnot given, it sets interval to zero and outputs packets as fast as they come back or one hun? dred times per second, whichever is more.Only the super-user may usethis option with zero interval.
Specify a timeout,in seconds, before ping exits regardless of how many packets have been sent or received.Inthiscase ping does not stop after count packet are sent, it waits either for deadline expire oruntil count probes are answered orfor some error notification from network.