NAME

     bing — compute point to point throughput using two sizes of ICMP ECHO_REQUEST packets to
     pairs of remote hosts.

SYNOPSIS

     bing [-dDnrRPvVwz] [-c count] [-e samples] [-f samplefile] [-i wait] [-p pattern]
          [-s small packetsize] [-S big packetsize] [-u size increment] host1 host2 [...]

DESCRIPTION

     Bing determines bandwidth on a point-to-point link by sending ICMP ECHO_REQUEST packets and
     measuring their roundtrip times for different packet sizes on each end of the link.

     host1 is supposed to be the nearest end of the link, while host2 is the other end.

     The options are as follows:

     -c count
             Stop after count resets of the stats. Useful only in conjunction with the -e option.
             Defaults to 1.

     -d      Set the SO_DEBUG option on the socket being used.

     -D      Display the measured throughput at every received packet.  By default, it is
             displayed only when the computed value changes, which itself changes only when the
             minimum roundtrip time for one of the packet sizes changes.

     -e samples
             Reset stats after sending samples ECHO_REQUEST packets.

     -f samplefile
             Saves the bandwidth measurements to the file samplefile.

     -i wait
             Wait wait seconds for each ECHO_REPLY packet.  The default is to wait for four
             seconds.

     -n      Numeric output only.  No attempt will be made to lookup symbolic names for host
             addresses.

     -P      Be pedantic regarding round-trip times.

             Normally, bing assumes that the roundtrip time for a small packet should always be
             smaller than the roundtrip time for a big packet to the same host, that for a given
             size the roundtrip time for host1 should always be smaller than the roundtrip time
             for host2, and that the increase in the roundtrip time between host1 and host2
             should always be bigger for big packets than for small packets.

             Bing takes advantage of this to better determine the minimum roundtrip times.

             Option -P disables this behaviour, in the unlikely event it could be of any use
             someday. Even IP/X25 links are not weird enough to require this, though.

     -p pattern
             You may specify up to 16 ``pad'' bytes to fill out the packet you send.  This is
             useful for diagnosing data-dependent problems in a network.  For example, “-p ff”
             will cause the sent packet to be filled with all ones.

     -R      Record route.  Includes the RECORD_ROUTE option in the ECHO_REQUEST packet and
             displays the route buffer on returned packets.  Note that the IP header is only
             large enough for nine such routes.  Many hosts ignore or discard this option.

     -r      Bypass the normal routing tables and send directly to a host on an attached network.
             If the host is not on a directly-attached network, an error is returned.  This
             option can be used to ping a local host through an interface that has no route
             through it (e.g., after the interface was dropped by routed(8) ).

     -s packetsize
             Specifies the number of data bytes to be sent in the small packets.  The default and
             minimum value is 8.

     -S packetsize
             Specifies the number of data bytes to be sent in the big packets.  The default is
             108.  The size should be chosen so that big packet roundtrip times are long enough
             to be accurately measured (depending on clock resolution and number of hops).

     -u size increment
             Specifies that bing should start sending packets of the size of small packetsize and
             then increase the size by size increment until it reaches big packetsize.

     -v      Verbose output.  ICMP packets other than ECHO_RESPONSE that are received are listed.

     -V      Very verbose output.  The roundtrip time of each received echo is displayed.

     -w      Display possible warnings about roundtrip times all the time.  By default, warnings
             are printed only at the end.

     -z      Fill packets with uncompressible (pseudo-random) data.

     Round-trip times and packet loss statistics are computed.  If duplicate packets are
     received, they are not included in the packet loss calculation, although the round trip time
     of these packets is used in calculating the minimum/average/maximum round-trip time numbers.
     When the specified number of loops have been made or if the program is terminated with a
     SIGINT, a brief summary is displayed.

     This program is intended for use in network testing, measurement and management.  Because of
     the load it can impose on the network, it is unwise to use bing during normal operations or
     from automated scripts.

BUGS

     Many Hosts and Gateways ignore the RECORD_ROUTE option.

     The maximum IP header length is too small for options like RECORD_ROUTE to be completely
     useful.  There's not much that that can be done about this, however.

     Some of the final stats (average throughputs) almost never give a even marginally correct
     result.

SEE ALSO

     netstat(1), ifconfig(8), ping(8), routed(8), traceroute(8)

AUTHOR

     Pierre Beyssac <pb@fasterix.freenix.fr>