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ipv4-heatmap(1) 	FreeBSD General Commands Manual        ipv4-heatmap(1)


ipv4-heatmap -- Create a map of IPv4 address data


ipv4-heatmap [-dhprm] [-A float] [-B float] [-a file] [-f font] [-k file] [-o file] [-s file] [-t string] [-u string] < iplist


ipv4-heatmap is a program that generates a map of IPv4 address data using a space-filling Hilbert Curve. Inspiration for ipv4-heatmap comes from the xkcd comic ( The output of ipv4-heatmap is a 4096x4096 PNG image. Each pixel in the image represents a single /24 network and is assigned one of 256 colors. Typically, the pixel color represents the number of hosts within the /24 belonging to a dataset or having some property, such as being pingable or being the source of some traffic. Pixel colors range from blue (1 host) to red (256 hosts), while black represents no data (0 hosts). Of course, the colors and pixel values may also be used to represent other properties of IPv4 addresses. The map may be annotated by placing transparent text labels over specific regions of address space. ipv4-heatmap also supports shading of areas specified by CIDR netblocks. This is useful to show reserved and other special address space, for example. ipv4-heatmap can also add an optional legend to the map. ipv4-heatmap uses the GD library (libgd) to create the map image.


The options are as follows: -A logmin Input data will be scaled logarithmically such that input values less than or equal to logmin will be set to 1. -B logmax Input data will be scaled logarithmically such that input values greater than or equal to logmax will be set to 255. -a annotations The annotations file contains a list of annotations for the map. See ANNOTATIONS below for the format of this file. -c color The color of the annotations (those that appear inside the map). Specified as 0xRRGGBB. -d increase debugging levels. -f font Specifies the font to use for the legend and annotations. If libgd was compiled with fontconfig support, then this can be a fontconfig string such as "Times-12:bold". Otherwise, you can also specify the pathname to a True Type Font (.ttf) file. -h Attach a horizontal legend to the bottom of the map. Note that the legend is drawn only if the -t option is given. -k keyfile Use keyfile to create the legend scale, rather than the built-in blue-to-red scale. -m Use Morton (aka "Z") Curve ordering instead of Hilbert. -o outfile Output file name. If none is given, the image is saved as map.png by default. -p Include a section in the legend that shows the size of CIDR pre- fixes. Boxes and labels will be drawn to show the size of /8, /12, /16, /20, and /24 prefixes. -r Reverse the background and foreground colors. -s shades The shades file can be used to shade certain areas of the map with specific colors and transparency levels. See SHADING below for the format of this file. -t title Instructs ipv4-heatmap to draw a legend for the map and place the title string in the top (or right) section. You may use "\n" to create multi-line titles. By default the legend will be drawn vertically and attached to the right side of the map. Use the -h option to create a horizontal legend instead. -u string Instructs ipv4-heatmap to draw a scale in the legend showing the range of colors and their values. string will be placed above the scale. Currently, ipv4-heatmap always assumes the data rep- resents some kind of utilization and prints percentages from 0 to 100% next to the scale. -y cidr Specifies the CIDR netblock that should be rendered. The default is to render the entire IPv4 space ( The "slash" value must be even so that the output image is square. The -y and -z options together determine the size of the output image. -z bits Specifies the number of address space bits assigned to each pixel in the output image. By default each pixel represents a /24 net- work, which corresponds to 8 host bits (i.e., 256 hosts). Spec- ify 0 here for one pixel per host address.


ipv4-heatmap accepts three input modes: 1. Increment mode. In this mode, the input consists of IPv4 addresses only, one address per line. Each address in the list increments the pixel value for the corresponding /24. In this mode, repeated addresses may lead to false results because ipv4-heatmap does not check for uniqueness of the input values. It silently limits pixels to the maximum value. The user should run the data through sort(1) and uniq(1) beforehand, if necessary. 2. Exact mode. In this mode, the input consists of two whitespace-separated fields: an IPv4 address and a color index. The color index is an integer in the range 0--255. Be careful with this mode because later addresses may overwrite earlier ones in the same /24. 3. Logarithmic mode. Very similar to Exact mode, except that the second column is loga- rithmically scaled to calculate the color index. In order to use this mode the input must have two fields, and the -A logmin and -B logmax command line options must be given. Color index k is calcu- lated from input value i according to this formula: ln ( i / logmin) k = 255 * -------------------- ln (logmax / logmin)


The annotations file consists of two or three TAB-separated fields. The first field is a CIDR prefix, and the second is the annotation string. The annotation string is rendered within the boundary of that prefix, centered both vertically and horizontally. The third field, if present, is also rendered just below the annotation text in a fixed-size 12-point font. If the third field is equal to the string "prefix" then the CIDR prefix (from field 1) is rendered instead. The annotations file might look like this, for example: HP DEC Apple The ipv4-heatmap source code distribution should include a file named iana-labels.txt, which is based on the list of IPv4 assignments made by IANA. The font can be selected with the -f command line option. At this time, however, the text color and transparency are hard-coded in the ipv4-heatmap program.


Areas of the map can be "shaded" by using the -s shades option. This was originally developed simply to highlight address space that is designated reserved or unallocated, but is also a useful way to render complex map data. The shades file consists of three TAB-separated fields: prefix, color, and alpha value. The CIDR prefix specifies the area to be shaded. The color should be specified has a hexadecimal value beginning with "0x". The alpha value controls the transparency of the shaded area and is passed directly to the GD library functions. An alpha value of 0 means full transparency, while a value of 127 means no transparency (full opacity). Here is an example that shows RFC 1918 address space in a light purple color: 0x7F7FFF 64 0x7F7FFF 64 0x7F7FFF 64


ipv4-heatmap uses a 12th-order Hilbert Curve to represnet the entire IPv4 address space. Locating a particular IP address along the curve can be confusing at first. Here is what a 2nd-order Hilbert curve looks like: 0---1 14--15 | | 3---2 13--12 | | 4 7---8 11 | | | | 5---6 9---10 The best way to understand how the Hilbert Curve works is to try drawing your own!


IPv4 Heatmap (C) 2007 The Measurement Factory, Inc Licensed under the GPL, version 2


ipv4-heatmap was written by Duane Wessels of The Measurement Factory, Inc. With contributions from: Roy Arends of Nominet UK.


Can't draw IPv6 address maps. The legends don't look all that great. You can use an image editing pro- gram like The Gimp to rearrange the legend and add better-looking text. FreeBSD 6.4 10 October, 2007 FreeBSD 6.4