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SC_ALLY(1)		  BSD General Commands Manual		    SC_ALLY(1)

     sc_ally --	scamper	driver to run Ally on a	list of	candidate aliases.

     sc_ally [-?D] [-i infile] [-o outfile] [-p	port] [-U unix-socket]
	     [-f fudge]	[-i probe-wait]	[-q attempts] [-t logfile]
	     [-w waittime]

     The sc_ally utility provides the ability to connect to a running
     scamper(1)	instance and have a set	of IPv4	address-pairs tested for
     aliases using the Ally technique.	For each address pair in the file,
     sc_ally establishes which probe methods (UDP, TCP-ack, ICMP-echo) solicit
     an	incrementing IP-ID value, and then uses	the Ally technique on pairs
     where a probe method is able to obtain an incrementing IP-ID for both ad-
     dresses.  The output is written to	a warts	file.  The options are as fol-

     -?	     prints a list of command line options and a synopsis of each.

     -D	     causes sc_ally to detach and become a daemon.

     -i	infile
	     specifies the name	of the input file which	consists of a sequence
	     of	IPv4 address-pairs, one	pair per line.

     -o	outfile
	     specifies the name	of the output file to be written.  The output
	     file will use the warts format.

     -p	port
	     specifies the port	on the local host where	scamper(1) is accept-
	     ing control socket	connections.

     -U	unix-socket
	     specifies the name	of a unix domain socket	where scamper(1) is
	     accepting control socket connections.

     -f	fudge
	     specifies the fudge factor	to use when (1)	inferring if IPIDs are
	     assigned from a counter, and (2) inferring	if two addresses share
	     the same counter.

     -i	probe-wait
	     specifies the inter-probe gap for both ping and Ally measure-
	     ments, in milliseconds.  The default is 1000ms (1 second);	the
	     minimum is	200ms, and the maximum is 2000ms.

     -q	attempts
	     specifies the number of times to try Ally when one	of the ad-
	     dresses is	unresponsive.

     -t	logfile
	     specifies the name	of a file to log output	from sc_ally generated
	     at	run time.

     -w	waittime
	     specifies the minimum length of time, in seconds, to wait between
	     completing	a measurement to a particular IP address and issuing
	     the next.

     Given a set of IPv4-address pairs in a file named infile.txt:

     and a scamper(1) daemon listening on port 31337, then these address-pairs
     can be tested for aliases using

     sc_ally -i	infile.txt -o outfile.warts -p 31337

     N.	Spring,	R. Mahajan, and	D. Wetherall, Measuring	ISP topologies with
     Rocketfuel, Proc. ACM SIGCOMM 2002.  scamper(1), sc_wartsdump(1),

     sc_ally was written by Matthew Luckie <>.

BSD				 March 1, 2011				   BSD


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