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| SC_PREFIXSCAN(1) | FreeBSD General Commands Manual | SC_PREFIXSCAN(1) |
NAME
sc_prefixscan —
SYNOPSIS
sc_prefixscan |
[-D]
[-i infile]
[-o outfile]
[-p port]
[-l logfile]
[-U unix-socket]
[-w wait]
[-x prefixlen] |
sc_prefixscan |
[-r data-file]
[-x prefixlen] |
DESCRIPTION
Thesc_prefixscan utility provides the ability to
connect to a running
scamper(1)
instance and use it to collect data to infer if an IPv4 link is likely a
point-to-point link using the prefixscan method. An address B is the in-bound
interface of a router in a traceroute path if we find an alias A' of the
address A returned for the previous hop and A' is a /31 or /30 mate of B, i.e.
the link between A and B is a point-to-point link. The prefixscan method
infers A and A' are aliases if the IPIDs in responses to five alternating
probes sent one second apart monotonically increase and differ by no more than
1,000, or probes to A and A' elicit responses with a common source address.
The first technique is a pairwise comparison similar to Ally, and the second
is the Mercator technique. The supported options to
sc_prefixscan are as follows:
-D- causes
sc_prefixscanto detach and become a daemon. -iinfile- specifies a file containing a list of IPv4 address pairs adjacent in traceroute paths to test if they are point-to-point links.
-ooutfile- specifies the name of the output file to be written during the data collection phase. The output file will use the warts(5) format.
-pport- specifies the port on the local host where scamper(1) is accepting control socket connections.
-llogfile- specifies the name of a file to log progress output from
sc_prefixscangenerated at run time. -rdata-file- specifies the name of the data file to be parsed for point-to-point link
inferences that were collected by
sc_prefixscanin a previous data collection. -Uunix-socket- specifies the name of a unix domain socket where a local scamper(1) instance is accepting control socket connections.
-wwait- specifies the length of time in seconds to wait between probing the same
IPv4 address with different methods. By default,
sc_prefixscanwaits five seconds between methods. -xprefixlen- specifies the maximum size of prefix to consider. By default,
sc_prefixscanconsiders up to an IPv4 /30 prefix.
EXAMPLES
Given a traceroute with the following path:traceroute to
192.0.30.641 192.0.2.12 192.0.32.103 192.0.31.84 192.0.30.64then to collect data to infer if the implied IPv4 links are point-to-point, put the links in a file named infile.txt formatted as follows:
192.0.2.1 192.0.32.10192.0.32.10 192.0.31.8192.0.31.8 192.0.30.64and use a scamper(1) daemon listening on port 31337 using:
sc_prefixscan -i infile.txt -o
outfile.warts -p 31337To obtain the inferred point-to-point links from outfile.warts:
sc_prefixscan -r
outfile.wartsSEE ALSO
scamper(1), sc_ally(1), sc_ipiddump(1), sc_wartsdump(1), sc_warts2text(1), sc_warts2json(1),M. Luckie and k. claffy, A Second Look at Detecting Third-party Addresses in Traceroute Traces with the IP Timestamp Option, Proc. Passive and Active Measurement Conference 2014.
R. Govindan and H. Tangmunarunkit, Heuristics for Internet Map Discovery, Proc. IEEE INFOCOM 2000.
N. Spring, R. Mahajan, and D. Wetherall, Measuring ISP topologies with Rocketfuel, Proc. ACM SIGCOMM 2002.
AUTHORS
sc_prefixscan was written by Matthew Luckie
<mjl@luckie.org.nz>.
| December 2, 2016 | FreeBSD 13.1-RELEASE |
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