ping(1M)ping(1M)NAMEping - send ICMP Echo Request packets to network host
SYNOPSIS
address-family] address] interval] ttl] host count timeout]]
address-family] address] interval] ttl] host packet-size count time‐
out]]
DESCRIPTION
The command sends ICMP Echo Request (ECHO_REQUEST) packets to the host
once per second. Each packet that is echoed back via an ICMP Echo
Response packet is written to the standard output, including round-trip
time.
ICMP Echo Request datagrams ("pings") have an IP and ICMP header, fol‐
lowed by a (see gettimeofday(2)) and an arbitrary number of "pad" bytes
used to fill out the packet. The default datagram length is 64 bytes,
but this can be changed by using the packet-size option.
Options
The following options and parameters are recognized by
If host is a multicast address, send multicast data‐
grams from the interface with the local IP address
specified by address in "dot" notation (see
inet(3N)). If the option is not specified, multi‐
cast datagrams are sent from the default interface,
which is determined by the route configuration. If
host is not a multicast address, the option is
ignored.
Insert an IP Record Route option in outgoing packets,
summarizing routes taken when the command termi‐
nates.
It may not be possible to get the round-trip path if
some hosts on the route taken do not implement the
IP Record Route option. A maximum of 9 Internet
addresses can be recorded due to the maximum length
of the IP option area.
The new Path MTU information is displayed when a ICMP
message is received from a gateway. The option must
be used in conjunction with a large packetsize and
with the option.
Bypass the normal routing tables and send directly
to a host on an attached network. If the host is
not on a directly-connected network, an error is
returned. This option can be used to ping the local
system through an interface that has no route
through it, such as, after the interface was dropped
by (see gated(1M)).
If host is a multicast address, set the time-to-live
field in the multicast datagram to ttl. This con‐
trols the scope of the multicast datagrams by speci‐
fying the maximum number of external systems through
which the datagram can be forwarded.
If ttl is zero, the datagram is restricted to the
local system. If ttl is one, the datagram is
restricted to systems that have an interface on the
network directly connected to the interface speci‐
fied by the option. If ttl is two, the datagram can
be forwarded through one multicast router at the
most; and so forth. zero to 255. The default value
is 1.
This option specifies the
interval in seconds, between each packet to be
transmitted. The default interval is 1 second.
Verbose output.
Show ICMP packets other than Echo Responses that are
received.
The address-family determines whether the host is an
IPv4 or IPv6 host. The address families currently
supported are for IPv4 addresses and for IPv6
addresses.
host Destination to which the ICMP Echo Requests are
sent. host can be a hostname or an IPv4 or IPv6
Internet address. All symbolic names specified for
host are looked up by using (see gethostent(3N)) for
IPv4, and (see getaddrinfo(3N)) for IPv6. If host
is an Internet address, it must be in "dot" notation
(see inet(3N)) for IPv4, and in "colon" notation
(see inet6(3N)) for IPv6.
If the address-family is specified, and host is an
Internet address, the address family of the Internet
address must be the same as that specified in the
address-family option. If the address-family is not
specified, and host is a symbolic name, an attempt
will be made to resolve host into an IPv4 address
first. If that fails, a second attempt will be made
to resolve host into an IPv6 address.
The ping command does not accept IPv4-mapped IPv6
addresses. To ping an IPv4 node, an IPv4 address
should be used. IPv4-mapped IPv6 addresses are used
to address IPv4-only nodes from an IPv6 node in a
socket program only. IPv4-mapped IPv6 addresses are
always converted to an IPv4 address before they are
used in packets sent over the network.
If a system does not respond as expected, the route
might be configured incorrectly on the local or
remote system or on an intermediate gateway, or
there might be some other network failure. Nor‐
mally, host is the address assigned to a local or
remote network interface.
(inet only) If host is a broadcast address, all sys‐
tems that receive the broadcast should respond.
Normally, these are only systems that have a network
interface on the same network as the local interface
sending the ICMP Echo Request.
If host is a multicast address, only systems that
have joined the multicast group should respond.
These may be distant systems if the option is speci‐
fied, and there is a multicast router on the network
directly connected to the interface specified by the
option.
packet-size The size of the transmitted packet, in bytes. By
default (when packet-size is not specified), the
size of transmitted packets is 64 bytes. The mini‐
mum value allowed for packet-size is 8 bytes, and
the maximum value is 65500 bytes. If packet-size is
smaller than 16 bytes, there is not enough room for
timing information. In that case, the round-trip
times are not displayed.
The number of packets
will transmit before terminating. The is not needed
if also specifying packet-size. Range: zero to
2147483647. The default is zero, in which case
sends packets until interrupted.
Override the default timeout value (10 seconds) which
uses to timeout (in seconds) when a host or network
is unreachable. This option is valid only with the
option or when count is specified. The option
should not be used with count equal to 0.
The option is not effective for reachable hosts or
networks.
Using ping for Fault Isolation
When using for fault isolation, first specify a local address for host
to verify that the local network interface is working correctly. Then
specify host and gateway addresses further and further away to deter‐
mine the point of failure. sends one datagram per second, and it nor‐
mally writes one line of output for every ICMP Echo Response that is
received. No output is produced if there are no responses. If an
optional count is given, only the specified number of requests is sent.
Round-trip times and packet loss statistics are computed. When all
responses have been received or the command times out (if the count
option is specified), or if the command is terminated with a a brief
summary is displayed.
This command is intended for use in testing, managing and measuring
network performance. It should be used primarily to isolate network
failures. Because of the load it could impose on the network, it is
considered discourteous to use unnecessarily during normal operations
or from automated scripts.
RETURN VALUE
exits with one of the following values:
On success.
On failure such as unknown host, illegal packet size, etc.
On a unreachable host or network.
AUTHOR
was developed in the Public Domain.
FILESSEE ALSOgetaddrinfo(3N), gethostent(3N), inet(3N), inet6(3N).
ping(1M)
