NAME¶

sc_prefixprober — scamper driver to probe addresses in specified prefixes

SYNOPSIS¶

DESCRIPTION¶

The sc_prefixprober utility provides the ability to connect to a running scamper(1) instance and use it to probe addresses in specified prefixes.

sc_prefixprober can probe both the first and a randomly-selected address in each prefix. When sc_prefixprober is instructed to probe both, sc_prefixprober will probe the addresses in a single prefix serially, and back-to-back so that measurements within a single prefix occur close in time.

The supplied prefixes can be nested. If a /24 prefix is contained in a less-specific /23, sc_prefixprober will probe addresses in both the specified /24, and the remaining /24 contained in the /23.

The command line options for sc_prefixprober are as follows:

-?

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

-v

prints the version of sc_prefixprober and exits.

-D

causes sc_prefixprober to detach and become a daemon.

-a in-file

specifies the name of the input file which consists of IPv4 and IPv6 prefixes, one per line. The input file can contain do-not-probe entries inline if they are prefixed with a - character.

-c command

specifies the command to use with each address. Valid commands are ping, trace, and tracelb. By default, sc_prefixprober uses trace.

-d duration

specifies the total duration allowed for all measurements. sc_prefixprober will space probing of individual prefixes out over the total duration specified. By default, sc_prefixprober probes prefixes as fast as allowed by scamper(1).

-l limit

specifies the number of objects to write to an output file, before closing it and opening the next file. The output file must contain a %u format specifier, which sc_prefixprober uses to embed a counter value that increments with each new output file. If the user uses the move option, sc_prefixprober moves the file when it closes the file.

-L list-attr

allows sc_prefixprober to override scamper(1) default values for list and cycle objects. The current choices for this option are:

• id=%u specify a 32-bit unsigned integer for the list id.
• name=%s specify a string for the list's name attribute.
• descr=%s specify a string for the list's description attribute.
• monitor=%s specify a string for the list's monitor attribute.
• cycle-id=%u specify a 32-bit unsigned integer for the cycle id.

-m move-dir

specifies the name of the directory to move completed files to. By default, sc_prefixprober leaves completed files in place.

-o out-file

specifies the prefix of the name of the output file to be written. The output file will use the warts(5) format, and can be compressed with gz, bz2, or xz at collection time if the specified outfile has the equivalent extension, or the output type was explicitly specified with -O

-O options

allows the behavior of sc_prefixprober to be further tailored. The current choices for this option are:

• first: probe first address in prefix.
• random: probe random address in prefix.
• noshuffle: do not shuffle probe order.
• warts.gz: compress warts output using gzip compression.
• warts.bz2: compress warts output using bzip2 compression.
• warts.xz: compress warts output using xz compression.

-p port

specifies the port on the local host where scamper(1) is accepting control socket connections.

-R unix-remote

specifies the unix domain socket on the local host where a remote scamper(1) instance is accepting commands.

-t log-file

specifies the name of a file to log output from sc_prefixprober generated at run time.

-U unix-local

specifies the unix domain socket on the local host where a local scamper(1) instance is accepting commands.

-x dnp-file

specifies a file containing prefixes whose addresses must not be probed. Do-not-probe entries may also be specified in the target file, each prefix preceded by a - character.

EXAMPLES¶

Given a set of prefixes in a file named infile.txt:

192.0.30.0/23
192.0.30.0/24
- 192.0.30.0/25
192.0.2.0/24

and a scamper(1) instance listening on port 31337, then both the first and a randomly selected address within each prefix can be tracerouted using ICMP-paris as follows:

In this scenario, sc_prefixprober may probe 192.0.30.129, 192.0.30.230, 192.0.31.1, 192.0.31.169, 192.0.2.1, and 192.0.2.233. These are addresses in the two specified /24s, and a /24 contained in the less-specific /23 that was not covered by a more-specific /24. sc_prefixprober did not probe any addresses in 192.0.30.0/25, as that is a do-not-probe entry. The output warts(5) file will have the list's name recorded as foo.

The following command writes a series of gzip-compressed warts(5) files, each of which have up to 1000 objects in them, with names such as outfile_0000.warts.gz, outfile_0001.warts.gz, moving them to the finished directory:

A user can concatenate these files into a final bzip2-compressed warts(5) file with sc_wartscat(1):

SEE ALSO¶

scamper(1), sc_wartscat(1), sc_wartsdump(1), sc_warts2json(1), warts(5)

AUTHORS¶

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