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rwnetmask(1) SiLK Tool Suite rwnetmask(1)
NAME
rwnetmask - Zero out lower bits of IP addresses in SiLK Flow records
SYNOPSIS
rwnetmask [--4sip-prefix-length=N] [--6sip-prefix-length=N]
[--4dip-prefix-length=N] [--6dip-prefix-length=N]
[--4nhip-prefix-length=N] [--6nhip-prefix-length=N]
[--sip-prefix-length=N] [--dip-prefix-length=N]
[--nhip-prefix-length=N] [--output-path=PATH]
[--print-filenames] [--ipv6-policy=POLICY]
[--note-add=TEXT] [--note-file-add=FILE]
[--compression-method=COMP_METHOD]
[--site-config-file=FILENAME]
{[--xargs] | [--xargs=FILENAME] | [FILE [FILE ...]]}
rwnetmask --help
rwnetmask --version
DESCRIPTION
rwnetmask reads SiLK Flow records, sets the prefix of the source IP,
destination IP, and/or next hop IP to the specified value(s) by masking
the least significant bits of the address(es), and writes the modified
SiLK Flow records to the specified output path. Modifying the IP
addresses allows one to group IPs into arbitrary CIDR blocks. Multiple
prefix-lengths may be specified; at least one must be specified.
When SiLK is compiled with IPv6 support, a separate mask can be
specified for IPv4 and IPv6 addresses. Records are processed using the
IP-version in which they are read. The --ipv6-policy switch can be
used to force the records into a particular IP-version or to ignore
records of a particular IP-version.
rwnetmask reads SiLK Flow records from the files named on the command
line or from the standard input when no file names are specified and
--xargs is not present. To read the standard input in addition to the
named files, use "-" or "stdin" as a file name. If an input file name
ends in ".gz", the file will be uncompressed as it is read. When the
--xargs switch is provided, rwnetmask will read the names of the files
to process from the named text file, or from the standard input if no
file name argument is provided to the switch. The input to --xargs
must contain one file name per line.
When no output path is specified and the standard output is not
connected to a terminal, rwnetmask writes the records to the standard
output.
OPTIONS
Option names may be abbreviated if the abbreviation is unique or is an
exact match for an option. A parameter to an option may be specified
as --arg=param or --arg param, though the first form is required for
options that take optional parameters.
One of these switches must be provided:
--4sip-prefix-length=N
--sip-prefix-length=N
For IPv4 addresses, specify the number of most significant bits of
the source address to keep. The default is to not mask off any
bits (i.e., N=32).
--4dip-prefix-length=N
--dip-prefix-length=N
For IPv4 addresses, specify the number of most significant bits of
the destination address to keep. The default is to not mask off
any bits (i.e., N=32).
--4nhip-prefix-length=N
--nhip-prefix-length=N
For IPv4 addresses, specify the number of most significant bits of
the next-hop address to keep. The default is to not mask off any
bits (i.e., N=32).
--6sip-prefix-length=N
For IPv6 addresses, specify the number of most significant bits of
the source address to keep. The default is to not mask off any
bits (i.e., N=128).
--6dip-prefix-length=N
For IPv6 addresses, specify the number of most significant bits of
the destination address to keep. The default is to not mask off
any bits (i.e., N=128).
--6nhip-prefix-length=N
For IPv6 addresses, specify the number of most significant bits of
the next-hop address to keep. The default is to not mask off any
bits (i.e., N=128).
These switches are optional:
--output-path=PATH
Write the output to the named PATH. PATH may be a file, named
pipe, or the symbols "stdout" or "-" to write to the standard
output. When not specified, output will be written to the standard
output. rwnetmask will exit with an error if the output path is
the standard output and the standard output is connected to a
terminal.
--print-filenames
Print to the standard error the names of the input files as the
files are opened.
--ipv6-policy=POLICY
Determine how IPv4 and IPv6 flows are handled when SiLK has been
compiled with IPv6 support. When the switch is not provided, the
SILK_IPV6_POLICY environment variable is checked for a policy. If
it is also unset or contains an invalid policy, the POLICY is mix.
When SiLK has not been compiled with IPv6 support, IPv6 flows are
always ignored, regardless of the value passed to this switch or in
the SILK_IPV6_POLICY variable. The supported values for POLICY
are:
ignore
Ignore any flow record marked as IPv6, regardless of the IP
addresses it contains. Only records marked as IPv4 will be
processed.
asv4
Convert IPv6 flow records that contain addresses in the
::ffff:0:0/96 prefix to IPv4 and ignore all other IPv6 flow
records.
mix Process the input as a mixture of IPv4 and IPv6 flows.
force
Convert IPv4 flow records to IPv6, mapping the IPv4 addresses
into the ::ffff:0:0/96 prefix.
only
Process only flow records that are marked as IPv6 and ignore
IPv4 flow records in the input.
--note-add=TEXT
Add the specified TEXT to the header of the output file as an
annotation. This switch may be repeated to add multiple
annotations to a file. To view the annotations, use the
rrwwffiilleeiinnffoo(1) tool.
--note-file-add=FILENAME
Open FILENAME and add the contents of that file to the header of
the output file as an annotation. This switch may be repeated to
add multiple annotations. Currently the application makes no
effort to ensure that FILENAME contains text; be careful that you
do not attempt to add a SiLK data file as an annotation.
--compression-method=COMP_METHOD
Specify how to compress the output. When this switch is not given,
output to the standard output or to named pipes is not compressed,
and output to files is compressed using the default chosen when
SiLK was compiled. The valid values for COMP_METHOD are determined
by which external libraries were found when SiLK was compiled. To
see the available compression methods and the default method, use
the --help or --version switch. SiLK can support the following
COMP_METHOD values when the required libraries are available.
none
Do not compress the output using an external library.
zlib
Use the zzlliibb(3) library for compressing the output, and always
compress the output regardless of the destination. Using zlib
produces the smallest output files at the cost of speed.
lzo1x
Use the lzo1x algorithm from the LZO real time compression
library for compression, and always compress the output
regardless of the destination. This compression provides good
compression with less memory and CPU overhead.
best
Use lzo1x if available, otherwise use zlib. Only compress the
output when writing to a file.
--site-config-file=FILENAME
Read the SiLK site configuration from the named file FILENAME.
When this switch is not provided, rwnetmask searches for the site
configuration file in the locations specified in the "FILES"
section.
--xargs
--xargs=FILENAME
Causes rwnetmask to read file names from FILENAME or from the
standard input if FILENAME is not provided. The input should have
one file name per line. rwnetmask will open each file in turn and
read records from it, as if the files had been listed on the
command line.
--help
Print the available options and exit.
--version
Print the version number and information about how SiLK was
configured, then exit the application.
EXAMPLES
In the following example, the dollar sign ("$") represents the shell
prompt. The text after the dollar sign represents the command line.
Lines have been wrapped for improved readability, and the back slash
("\") is used to indicate a wrapped line.
To summarize the TCP traffic from your network to each /24 on the
Internet, use:
$ rwfilter --type=out,outweb --proto=6 --pass=stdout \
| rwnetmask --dip-prefix-length 24 \
| rwaddrcount --use-dest --sort --print-rec
IP Address| Bytes|Packets|Records| Start Time|...
10.10.35.0| 2345| 52| 6|01/15/2003 19:30:31|
10.23.3.0| 118| 2| 1|01/16/2003 19:38:40|
10.23.4.0| 20858| 263| 16|01/16/2003 16:54:25|
10.31.49.0|266920| 3885| 1092|01/11/2003 02:04:11|
10.126.7.0| 36912| 260| 9|01/16/2003 17:03:28|
....
ENVIRONMENT
SILK_IPV6_POLICY
This environment variable is used as the value for --ipv6-policy
when that switch is not provided.
SILK_CLOBBER
The SiLK tools normally refuse to overwrite existing files.
Setting SILK_CLOBBER to a non-empty value removes this restriction.
SILK_CONFIG_FILE
This environment variable is used as the value for the
--site-config-file when that switch is not provided.
SILK_DATA_ROOTDIR
This environment variable specifies the root directory of data
repository. As described in the "FILES" section, rwnetmask may use
this environment variable when searching for the SiLK site
configuration file.
SILK_PATH
This environment variable gives the root of the install tree. When
searching for configuration files, rwnetmask may use this
environment variable. See the "FILES" section for details.
FILES
${SILK_CONFIG_FILE}
${SILK_DATA_ROOTDIR}/silk.conf
/data/silk.conf
${SILK_PATH}/share/silk/silk.conf
${SILK_PATH}/share/silk.conf
/usr/local/share/silk/silk.conf
/usr/local/share/silk.conf
Possible locations for the SiLK site configuration file which are
checked when the --site-config-file switch is not provided.
SEE ALSO
rrwwffiilleeiinnffoo(1), ssiillkk(7), zzlliibb(3)
SiLK 3.11.0.1 2016-02-19 rwnetmask(1)