NAME

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

SYNOPSIS

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

       sc_ally [-d dump-id] [-O options] [file ...]

DESCRIPTION

       The  sc_ally  utility  provides the ability to connect to a running scamper(1) instance and have a set of
       IPv4 address sets tested for aliases using the Ally technique.  For each address pair on a single line 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.   sc_ally  can  also infer which IP addresses are aliases using the Mercator
       common source address technique as a byproduct of the UDP probing  that  sc_ally  does.   The  output  of
       sc_ally  is  written to a warts(5) file, which can then be processed to extract aliases.  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.

       -a infile
               specifies the name of the input file  which  consists  of  a  sequence  of  IPv4  addresses,  one
               candidate set 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.

       -d dump-id
               specifies the number identifying an analysis to conduct.  The current choices for  are  1-3,  and
               are:
                 -  1: dump aliases inferred using the Ally (IPID-based) technique.
                 -  2: dump aliases inferred using the Mercator (common source address based) technique.
                 -  3: dump aliases inferred using both Ally and Mercator techniques.

       -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.  A value of zero will cause ally to  infer
               aliases if the IPIDs are in a monotonic sequence.

       -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.

       -O options
               allows the behavior of sc_ally to be further tailored.  The current choices for this option are:
                 -  nobs: do not consider byte swapped IPID values when inferring if IPID  values  are  assigned
                    from a counter.
                 -  tc: dump transitive closure when reporting aliases.

       -q attempts
               specifies the number of probes to use with Ally.

       -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.

EXAMPLES

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

          192.0.2.1 192.0.32.10 192.0.31.60
          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 addresses can be tested for aliases using

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

       To obtain a list of inferred alias pairs using the Ally technique from a warts(5) file:

       sc_ally -d 1 outfile.warts

       To obtain a list of inferred routers using a transitive closure of alias pairs inferred  using  the  Ally
       and Mercator techniques:

       sc_ally -d 3 -O tc outfile.warts

SEE ALSO

       scamper(1), sc_radargun(1), sc_wartsdump(1), sc_warts2text(1),

       N.  Spring,  R.  Mahajan,  and  D. Wetherall, Measuring ISP topologies with Rocketfuel, Proc. ACM SIGCOMM
       2002.

       R. Govindan and H. Tangmunarunkit, Heuristics for Internet Map Discovery, Proc. IEEE INFOCOM 2000.

       A. Bender, R. Sherwood, and N.  Spring,  Fixing  Ally's  growing  pains  with  velocity  modeling,  Proc.
       ACM/SIGCOMM Internet Measurement Conference 2008.

AUTHORS

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

Debian                                             May 4, 2019                                        SC_ALLY(1)