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bwping(8)		    System Manager's Manual		     bwping(8)

       bwping  and  bwping6  are tools to measure bandwidth and	response times
       between two hosts using Internet	Control	Message	Protocol  (ICMP)  echo
       request/echo reply mechanism.

       bwping [	-4 | -6	] [ -u buf_size	] [ -r reporting_period	] [ -T tos(v4)
       | traf_class(v6)	] [ -B bind_addr ] -b kbps -s pkt_size -v volume  tar-

       bwping6	[  -4  |  -6  ]	 [  -u buf_size	] [ -r reporting_period	] [ -T
       tos(v4) | traf_class(v6)	] [ -B bind_addr ] -b kbps -s pkt_size -v vol-
       ume target

       -4   Forces IPv4	mode. Default mode of operation	is IPv4	for bwping and
	    IPv6 for bwping6 otherwise.

       -6   Forces IPv6	mode. Default mode of operation	is IPv4	for bwping and
	    IPv6 for bwping6 otherwise.

       -u buf_size
	    Sets  the  size of the socket send/receive buffer in bytes.	If not
	    specified, the system default will be used.	Tune this parameter if
	    the	 speed measurement results are unexpectedly low	or packet loss

       -r reporting_period
	    Sets the interval time in seconds between periodic bandwidth, RTT,
	    and	 loss reports. If zero,	there will be no periodic reports (de-

       -T tos(v4) | traf_class(v6)
	    Sets the TOS (in IPv4 mode)	or Traffic Class (in IPv6 mode)	 value
	    of outgoing	ip packets. Default value is zero.

       -B bind_addr
	    Sets the source address of outgoing	ip packets. By default the ad-
	    dress of the outgoing interface will be used.

       -b kbps
	    Sets the transfer speed in kilobits	per second.

       -s pkt_size
	    Sets the size of  ICMP  packet  (excluding	IPv4/IPv6  header)  in

       -v volume
	    Sets the volume to transfer	in bytes.

       Oleg Derevenetz <>

       None known.

       These tools use raw sockets to deal with	ICMP messages, so they may re-
       quire root privileges or	extended capabilities (such as CAP_NET_RAW  on
       Linux) to run. They can also be run as setuid root.

       Although	 bwping	 and  bwping6 does not require any special software on
       the remote host (only the ability to respond on ICMP echo request  mes-
       sages),	there are some special requirements to network infrastructure,
       local and remote	host performance:

       1. There	should be no ICMP echo request/reply filtering on the network.
       This includes QoS mechanisms (which often affects ICMP) at any point in
       the testing path;

       2. Local	host should have enough	CPU resources to send  ICMP  echo  re-
       quest  messages with given rate,	and remote host	should quickly respond
       on these	messages and should have no ICMP bandwidth limiting turned on.

       If some of these	requirements are not satisfied	then  the  measurement
       results	will be	inadequate or fail completely. In general, for testing
       bandwidth where QoS is  implemented,  always  test  with	 traffic  that
       matches the QoS class to	be tested.

       netstat(1), ping(8)



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