NAME

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

SYNOPSIS

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

DESCRIPTION

     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 addresses.  The output is written to
     a warts file.  The options are as follows:

     -?      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 accepting 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 measurements, 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 addresses 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.

EXAMPLE

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

        192.0.2.1 192.0.32.10
        192.0.2.2 192.0.31.8
        192.0.2.3 192.0.30.64

     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

SEE ALSO

     N. Spring, R. Mahajan, and D. Wetherall, Measuring ISP topologies with Rocketfuel, Proc. ACM
     SIGCOMM 2002.  scamper(1), sc_wartsdump(1), sc_warts2text(1)

AUTHORS

     sc_ally is written by Matthew Luckie <mjl@luckie.org.nz>.