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	    <TITLE>FlowScan - a system to analyze and report on cflowd flow files

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<!-- INDEX BEGIN -->

<UL>

	<LI><A HREF="#NAME">NAME</A>
	<LI><A HREF="#DESCRIPTION">DESCRIPTION</A>
	<LI><A HREF="#Use_the_Mailing_List">Use the Mailing List</A>
	<LI><A HREF="#Upgrading">Upgrading</A>
	<UL>

		<LI><A HREF="#Software_Upgrade_Requirements">Software Upgrade Requirements</A>
		<LI><A HREF="#Configuring_FlowScan_when_Upgrad">Configuring FlowScan when Upgrading</A>
		<LI><A HREF="#Generating_Graphs_after_Upgradin">Generating Graphs after Upgrading</A>
		<LI><A HREF="#Done_Upgrading">Done Upgrading </A>
	</UL>

	<LI><A HREF="#Initial_Install_Requirements">Initial Install Requirements</A>
	<UL>

		<LI><A HREF="#Hardware_Requirements">Hardware Requirements</A>
		<LI><A HREF="#Software_Requirements">Software Requirements</A>
	</UL>

	<LI><A HREF="#Configuring_FlowScan_Prerequisit">Configuring FlowScan Prerequisites</A>
	<UL>

		<LI><A HREF="#Choose_a_User_to_Run_cflowd_and_">Choose a User to Run cflowd and FlowScan</A>
		<LI><A HREF="#Configuring_Your_Host">Configuring Your Host</A>
		<LI><A HREF="#Configuring_Your_Ciscos">Configuring Your Ciscos</A>
		<LI><A HREF="#Configuring_cflowd">Configuring cflowd</A>
	</UL>

	<LI><A HREF="#Configuring_FlowScan">Configuring FlowScan</A>
	<UL>

		<LI><A HREF="#Configure_and_Install">Configure and Install</A>
		<LI><A HREF="#Create_the_Output_Directory">Create the Output Directory</A>
		<LI><A HREF="#FlowScan_Configuration_Files">FlowScan Configuration Files</A>
		<LI><A HREF="#Preserving_Old_Flow_Files">Preserving "Old" Flow Files</A>
	</UL>

	<LI><A HREF="#Testing_FlowScan">Testing FlowScan</A>
	<LI><A HREF="#Performance_Problems_">Performance Problems?</A>
	<LI><A HREF="#Final_Setup">Final Setup</A>
	<LI><A HREF="#Generating_Graphs">Generating Graphs</A>
	<UL>

		<LI><A HREF="#Supplied_Graphs">Supplied Graphs</A>
		<LI><A HREF="#Adding_Events_to_Graphs">Adding Events to Graphs</A>
		<LI><A HREF="#Custom_Graphs">Custom Graphs</A>
		<LI><A HREF="#Future_Directions_for_Graphs">Future Directions for Graphs</A>
	</UL>

	<LI><A HREF="#Copyright_and_Disclaimer">Copyright and Disclaimer</A>
</UL>
<!-- INDEX END -->

<HR>
<P>
<H1><A NAME="NAME">NAME

</A></H1>
FlowScan - a system to analyze and report on cflowd flow files


<P>

<P>
<HR>
<H1><A NAME="DESCRIPTION">DESCRIPTION

</A></H1>
This document is the FlowScan User Manual $Revision: 1.23 $, $Date:
2001/02/28 21:48:08 $. It describes the installation and setup of <CODE>FlowScan-1.006</CODE>.


<P>

FlowScan is a system which scans cflowd-format raw flow files and reports
on what it finds. There are two report modules that are included. The <CODE>CampusIO</CODE> report module produced the graphs at:


<P>

<PRE>   <A HREF="http://wwwstats.net.wisc.edu">http://wwwstats.net.wisc.edu</A>
</PRE>

<P>

which show traffic in and out through a peering point or network border.
The <CODE>SubNetIO</CODE> report updates RRD files for each of the subnets that you specify (so that
you can produce graphs of <CODE>CampusIO</CODE>
by subnet).


<P>

The idea behind the distinct report modules is that users will be able to
write new reports that are either derived-classes from <CODE>CampusIO</CODE>
or altogether new ones. For instance, one may wish to write a report module
called <CODE>Abuse</CODE> which would send email when it detected potentially abusive things going
on, like Denial-of-Service attacks and various scans.


<P>

FlowScan is freely-available under the GPL, the GNU General Public License.


<P>

<P>
<HR>
<H1><A NAME="Use_the_Mailing_List">Use the Mailing List

</A></H1>
Please help me to help you. It is, unfortunately, not uncommon for one to
have questions or problems while installing FlowScan. Please do not send
email about such things to my personal email address, but instead check the
FlowScan mailing list archive, and join the FlowScan mailing list.
Information about the FlowScan mailing lists can be found at:


<P>

<PRE>   <A HREF="http://net.doit.wisc.edu/~plonka/FlowScan/#Mailing_Lists">http://net.doit.wisc.edu/~plonka/FlowScan/#Mailing_Lists</A>
</PRE>

<P>

By reading and participating in the list, you will be helping me to use my
time effectively so that others will benefit from questions answered and
issues raised.


<P>

The mailing lists' archives are available at:


<P>

<PRE>   <A HREF="http://net.doit.wisc.edu/~plonka/list/flowscan">http://net.doit.wisc.edu/~plonka/list/flowscan</A>
</PRE>

<P>

and:


<P>

<PRE>   <A HREF="http://net.doit.wisc.edu/~plonka/list/flowscan-announce">http://net.doit.wisc.edu/~plonka/list/flowscan-announce</A>
</PRE>

<P>

<P>
<HR>
<H1><A NAME="Upgrading">Upgrading

</A></H1>
<STRONG>First-time</STRONG> FlowScan users should skip to <A HREF="#Initial_Install_Requirements">Initial Install Requirements</A>, below.


<P>

If you have previously installed and properly configured
<CODE>FlowScan-1.005</CODE>, you need only perform a subset of the steps that one would normally have
to perform for an initial installation.


<P>

This release of FlowScan uses more memory than previous releases. That is,
the <CODE>flowscan</CODE> process will grow to a larger size than that in
<CODE>FlowScan-1.005</CODE>. In my recent experience while testing this release, the <CODE>flowscan</CODE> process size to approximately 128MB when I use the new experimental <CODE>BGPDumpFile</CODE> option to produce ``Top'' reports by ASN. This is hopefully understandable
since <CODE>flowscan</CODE> is carrying a full internet routing table when configured in this way. The
memory requirements are significantly lessened if you do not use the
<CODE>BGPDumpFile</CODE> option. The <CODE>flowscan</CODE> process' size is also a function of the number of active hosts in your
network.


<P>

<P>
<HR>
<H2><A NAME="Software_Upgrade_Requirements">Software Upgrade Requirements

</A></H2>
<UL>
<LI><STRONG><A NAME="item_Upgrading">Upgrading perl Modules

</A></STRONG>
Upgrade the <CODE>Cflow</CODE> perl module to <CODE>Cflow-1.030</CODE> or later for improved performance. Install <CODE>HTML::Table</CODE> in case you want to produce the new ``Top Talkers'' reports. Details on how
to obtain and install these modules can be found in <A HREF="#Software_Requirements">Software Requirements</A>, below.


<P>

<LI><STRONG><A NAME="item_Upgrading">Upgrading FlowScan

</A></STRONG>
Of course, when upgrading you will need to obtain the current FlowScan.
When you run <EM>configure</EM>, you should specify the same value with <CODE>--prefix</CODE> that you did when installing your existing FlowScan, e.g.  <EM>/var/local/flows</EM>, or wherever your time-stamped raw flow files are currently being written
by <CODE>cflowd</CODE>.


<P>

</UL>
<P>
<HR>
<H2><A NAME="Configuring_FlowScan_when_Upgrad">Configuring FlowScan when Upgrading

</A></H2>
There is now POD documentation provided with the CampusIO and SubNetIO
reports. Please use that as the definitive reference on configuration
options for those reports, e.g.:


<P>

<PRE>   $ cd bin
   $ perldoc CampusIO
</PRE>

<P>

Here are a few things that changed regarding the FlowScan configuration:


<P>

<DL>
<DT><STRONG><A NAME="item_Upgrading">Upgrading CampusIO and/or SubNetIO Configuration Files

</A></STRONG><DD>
There are new <CODE>TopN</CODE> and <CODE>ReportPrefixFormat</CODE> directives for
<CODE>CampusIO</CODE> and <CODE>SubNetIO</CODE>. These directives enable the production of ``Top Talker'' reports.
Furthermore there are new <STRONG>experimental</STRONG>

<CODE>BGPDumpFile</CODE> and <CODE>ASNFile</CODE> options <CODE>CampusIO</CODE> which are used to produce ``Top'' reports by Autonomous System. You will
need access a Cisco carrying a full BGP routing table to produce such
reports. See the CampusIO configuration documentation for more info about
configuring this feature. If you have trouble with it, remember that it is
experimental, so please join the discussion in the mailing list.


<P>

Secondly, the <EM>Napster_subnets.boulder</EM> has changed significantly since that provided with FlowScan-1.005. If you
have FlowScan configured to measure Napster traffic, replace your old
<EM>Napster_subnets.boulder</EM> with the one from the newer distribution:


<P>

<PRE>   $ cp cf/Napster_subnets.boulder $PREFIX/bin/Napster_subnets.boulder
</PRE>

<P>

<DT><STRONG>Upgrading your RRD Files

</A></STRONG><DD>
If you are upgrading, it is necessary to add two new Data Sources to the
some of your existing RRD files. Before running flowscan, backup your RRD
files, e.g.:


<P>

<PRE>   $ cd $prefix/graphs
   $ tar cf saved_rrd_files.tar *.rrd
</PRE>

<P>

then do this:


<P>

<PRE>   $ cd $prefix/graphs
   $ ../bin/add_txrx total.rrd [1-9]*.*.*.*_*.rrd
</PRE>

<P>

</DL>
<P>
<HR>
<H2><A NAME="Generating_Graphs_after_Upgradin">Generating Graphs after Upgrading

</A></H2>
A number of new features have been added to the <EM>graphs.mf</EM> template Makefile. Some of these are described below in <A HREF="#Supplied_Graphs">Supplied Graphs</A>. You may wish to copy <EM>graphs.mf</EM> to your <EM>graphs</EM>
sub-directory.


<P>

While it is not required, I highly recommend installing <CODE>RRGrapher</CODE> if you want to produce other graphs. It is referenced below in <A HREF="#Custom_Graphs">Custom Graphs</A>.


<P>

<P>
<HR>
<H2><A NAME="Done_Upgrading">Done Upgrading 

</A></H2>
That should be it for upgrading!


<P>

<P>
<HR>
<H1><A NAME="Initial_Install_Requirements">Initial Install Requirements

</A></H1>
<P>
<HR>
<H2><A NAME="Hardware_Requirements">Hardware Requirements

</A></H2>
<UL>
<LI><STRONG><A NAME="item_Cisco">Cisco routers

</A></STRONG>
If you don't have Cisco at your border, you're probably barking up the
wrong tree with this package. Also, FlowScan currently requires that your
IOS version supports NetFlow version 5. Try this command on your router if
you are unsure:


<P>

<PRE>   ip flow-export version ?
</PRE>

<P>

<LI><STRONG><A NAME="item_a">a GNU/Linux or Unix machine

</A></STRONG>
If you have a trivial amount of traffic being exported to cflowd, such as a
T1's worth, perhaps any old machine will do.


<P>

However, if you want to process a fair amount of traffic (e.g. at ~OC-3
rates) you'll want a <EM>fast</EM> machine.


<P>

I've run FlowScan on a SPARC Ultra-30 w/256MB running Solaris 2.6, a Dell
Precision 610 (dual Pentium III, 2x450Mhz) w/128MB running Debian Linux
2.1, and most recenlty a dual PIII Dell server, 2x600Mhz, w/256MB running
Debian Linux 2.2r2. The Intel machines are definitely preferably in the
sense that <CODE>flowscan</CODE> processes flows in about 40% of the time that it took the SPARC. (The main <CODE>flowscan</CODE> script itself is currently single-threaded.)


<P>

In an early performance test of mine, using 24 hours of flows from our
peering router here at UW-Madison, here's the comparison of their ave. time
to process 5 minutes of flows:


<P>

<PRE>   SPARC - 284 sec
   Intel - 111 sec
</PRE>

<P>

Note that it is important that flowscan doesn't take longer to process the
flows than it does for your network's activity and exporting Cisco routers
to produce the flows. So, you want to keep the time to process 5 minutes of
flows under 300 seconds on average.


<P>

My recent testing has indicated that 600-850MHz PIII machines can usually
process 3000-4000 flows per second, if <CODE>flowscan</CODE> doesn't have to compete with too many other processes.


<P>

<LI><STRONG><A NAME="item_Disk">Disk Space

</A></STRONG>
I recommend devoting a file-system to cflowd and FlowScan. Both require
disk space and the amount depends upon a number of things:


<P>

<UL>
<LI><STRONG><A NAME="item_The">The rate of flows being exported and collected

</A></STRONG>
<LI><STRONG><A NAME="item_The">The rate at which FlowScan is able to process (and remove) those files

</A></STRONG>
<LI><STRONG><A NAME="item_Whether">Whether or not you have configured FlowScan to "save" flow files

</A></STRONG>
<LI><STRONG><A NAME="item_The">The number of hours after which you remove gzip(1)ped flow files

</A></STRONG>
</UL>
To find the characteristics of your environment, you'll just have to run
the patched cflowd for a little while to see what you get.


<P>

Early in this project (c. 1999), we were usually collecting about
150-300,000 flows from our peering router every 5 minutes. Recently, our
5-minute flow files average ~15 to 20 MB in size.


<P>

During a recent inbound Denial-of-Service attack consisting of 40-byte TCP
SYN packets with random source addresses and port numbers, I've seen a
single ``5-minute'' flow file greater than 500MB! Even on our fast machine,
that single file took hours to process.


<P>

Surely YMMV, currently a 35GB file-system allows us to preserve
<CODE>gzip(1)</CODE>ped flow files for about 2 weeks.


<P>

<LI><STRONG><A NAME="item_Network">Network Interface Card

</A></STRONG>
Regarding the host machine configuration, consider the amount of traffic
that may be exported from your <CODE>Cisco(s)</CODE> to your collector
machine if you have enabled <CODE>ip route-cache flow</CODE> on very many fast interfaces. With lots of exported flow data (e.g. 15-20
MB of raw flow file data every 5 minutes) and only a 10 Mb/s ethernet NIC,
I found that the host was dropping some of the incoming UDP packets, even
though the rate of incoming flows was less than 2 Mb/s. This was evidenced
by a constantly-increasing number of <CODE>udpInOverflows</CODE> in the
<CODE>netstat -s</CODE> output under Solaris. I addressed this by reconfiguring my hosts with a 100
Mb/s fast ethernet NIC or 155 Mb/s OC-3 ATM LANE interface and have not
seen that problem since. Of course, one should assure that the requisite
bandwidth is available along the full path between the exporting
<CODE>Cisco(s)</CODE> and the collecting host.


<P>

</UL>
<P>
<HR>
<H2><A NAME="Software_Requirements">Software Requirements

</A></H2>
The packages and perl modules required by FlowScan are numerous. Their
presence or absence will be detected by FlowScan's <EM>configure</EM> script but you'll save yourself some frustration by getting ahead of the
game by collecting and installing them first. Below, I've attempted to
present them in a reasonable order in which to obtain, build, and install
them.


<P>

<UL>
<LI><STRONG><A NAME="item_arts">arts++

</A></STRONG>
arts++ is required by cflowd and is available at:


<P>

<PRE>   <A HREF="ftp://ftp.caida.org/pub/arts++/">ftp://ftp.caida.org/pub/arts++/</A>
</PRE>

<P>

As of arts++-1-1-a5, the arts++ build appears to require GNU make 3.79
because its Makefiles use glob for header dependencies, e.g. ``*.hh''. From
my cursory look at the GNU make ChangeLog, perhaps any version &gt;=
3.78.90 will suffice. Also there may be trouble if you don't have flex
headers installed in your ``system'' include directory, such as
``/usr/include'', even though ``configure.in'' appears to be trying to
handle this situation. Since mine were in the ``local'' include directory,
I hand-tweaked the classes/src/Makefile's ``.cc.o'' default rule to include
that directory as well.


<P>

<LI><STRONG><A NAME="item_cflowd">cflowd patch

</A></STRONG>
My patches are available at:


<P>

<PRE>   <A HREF="http://net.doit.wisc.edu/~plonka/cflowd/?M=D">http://net.doit.wisc.edu/~plonka/cflowd/?M=D</A>
</PRE>

<P>

Obtain the patch or patches which apply to the version of cflowd that you
intend to run and apply it to cflowd before building cflowd below.


<P>

<LI><STRONG><A NAME="item_cflowd">cflowd

</A></STRONG>
cflowd itself is available at:


<P>

<PRE>   <A HREF="http://www.caida.org/tools/measurement/cflowd/">http://www.caida.org/tools/measurement/cflowd/</A>
   <A HREF="ftp://ftp.caida.org/pub/cflowd/">ftp://ftp.caida.org/pub/cflowd/</A>
</PRE>

<P>

In my experience with building cflowd, you're the most likely to have
success in a GNU development environment such as that provided with
GNU/Linux or FreeBSD.


<P>

I have not had problems building the patched <CODE>cflowd-2-1-a9</CODE> or
<CODE>cflowd-2-1-a6</CODE> under Debian Linux 2.2.


<P>

I've also managed to build the patched cflowd-2-1-a6 with gcc-2.95.2 and
binutils-2.9.1 on a sparc-sun-solaris2.6 machine with GNU make 3.79 and
flex-2.5.4.


<P>

As of cflowd-2-1-a6, beware that during the build may pause for minutes
while <CODE>as(1)</CODE> uses lots of CPU and memory to building
``CflowdCisco.o''. This is apparenly `normal'. Also, the build appears to
be subtley reliant on GNU <CODE>ld(1),</CODE> which is available in the GNU
``binutils'' package. (I was unable to build cflowd-2-1-a6 with the
sparc-sun-solaris2.6 ``/usr/ccs/bin/ld'' although earlier cflowd releases
built fine with it.)


<P>

<LI><STRONG><A NAME="item_perl">perl 5

</A></STRONG>
If you don't have this already, you're probably way over your head, but
anyway, check out the Comprehensive Perl Archive Network (CPAN):


<P>

<PRE>   <A HREF="http://www.cpan.org/">http://www.cpan.org/</A>
</PRE>

<P>

and:


<P>

<PRE>   <A HREF="http://www.perl.com/">http://www.perl.com/</A>
</PRE>

<P>

I've tested with perl 5.004, 5.005, and 5.6.0. If you'd like to upgrade to
perl 5.6.0 you can install it thusly:


<P>

<PRE>   # perl -MCPAN -e shell
   cpan&gt; install G/GS/GSAR/perl-5.6.0.tar.gz
</PRE>

<P>

However, I suggest you don't install it in the same place as your existing <CODE>perl</CODE>.


<P>

<LI><STRONG><A NAME="item_Korn">Korn shell

</A></STRONG>
<CODE>ksh</CODE> is used as the <CODE>SHELL</CODE> in the <EM>Makefile</EM> for the graphs.
<CODE>pdksh</CODE> works fine too. If for some reason you don't already have
<CODE>ksh</CODE>, check out:


<P>

<PRE>   <A HREF="http://www.kornshell.com/">http://www.kornshell.com/</A>
</PRE>

<P>

or:


<P>

<PRE>   <A HREF="http://www.math.mun.ca/~michael/pdksh/">http://www.math.mun.ca/~michael/pdksh/</A>
</PRE>

<P>

If you're using GNU/Linux, <CODE>pdksh</CODE> is available as an optional binary package for various distributions.


<P>

<LI><STRONG><A NAME="item_RRDTOOL">RRDTOOL

</A></STRONG>
This package is available at:


<P>

<PRE>   <A HREF="http://ee-staff.ethz.ch/~oetiker/webtools/rrdtool/">http://ee-staff.ethz.ch/~oetiker/webtools/rrdtool/</A>
</PRE>

<P>

I recommend that you install <CODE>rrdtool</CODE> from source, even if it is available as an optional binary package for
operating system distribution. This is because FlowScan expects that you've
built and installed RRDTOOL something like this:


<P>

<PRE>   $ ./configure --enable-shared
   $ make install site-perl-install
</PRE>

<P>

That last bit is important, since it makes the <CODE>rrdtool</CODE> perl modules available to all perl scripts.


<P>

<LI><STRONG><A NAME="item_Perl">Perl Modules

</A></STRONG>
<UL>
<LI><STRONG><A NAME="item_RRDs">RRDs

</A></STRONG>
This is the shared-library perl module supplied with <CODE>rrdtool</CODE>. (See above.)


<P>

<LI><STRONG><A NAME="item_Boulder">Boulder

</A></STRONG>
The Boulder distribution includes the Boulder::Stream module and its
prerequisites. They are available on CPAN in the ``Boulder'' distribution.


<P>

You can install them using the CPAN shell like this:


<P>

<PRE>   # perl -MCPAN -e shell
   cpan&gt; install Boulder::Stream
</PRE>

<P>

If you want to fetch it manually you can probably find it at:


<P>

<PRE>   <A HREF="http://search.cpan.org/search?dist=Boulder">http://search.cpan.org/search?dist=Boulder</A>
</PRE>

<P>

I've tested with the modules supplied in the Boulder-1.18 distribution and
also those in the old ``boulder.tar.gz'' distribution.


<P>

<LI><STRONG><A NAME="item_ConfigReader">ConfigReader::DirectiveStyle

</A></STRONG>
The ConfigReader package is available on CPAN. You can install it using the
CPAN shell like this:


<P>

<PRE>   # perl -MCPAN -e shell
   cpan&gt; install ConfigReader::DirectiveStyle
</PRE>

<P>

If you want to fetch it manually you can probably find it at:


<P>

<PRE>   <A HREF="http://search.cpan.org/search?dist=ConfigReader">http://search.cpan.org/search?dist=ConfigReader</A>
</PRE>

<P>

I'm using ConfigReader-0.5.


<P>

<LI><STRONG><A NAME="item_HTML">HTML::Table

</A></STRONG>
The HTML::Table package is available on CPAN. You can install it using the
CPAN shell like this:


<P>

<PRE>   # perl -MCPAN -e shell
   cpan&gt; install HTML::Table
</PRE>

<P>

If you want to fetch it manually you can probably find it at:


<P>

<PRE>   <A HREF="http://search.cpan.org/search?dist=HTML-Table">http://search.cpan.org/search?dist=HTML-Table</A>
</PRE>

<P>

<LI><STRONG><A NAME="item_Net">Net::Patricia

</A></STRONG>
This is a new module which I have uploaded to PAUSE, but it not have
entered CPAN yet.


<P>

You can try to install it using the CPAN shell like this:


<P>

<PRE>   # perl -MCPAN -e shell
   cpan&gt; install Net::Patricia
</PRE>

<P>

If <CODE>Net::Patricia</CODE> is not found on CPAN, you can obtain it here:


<P>

<PRE>   <A HREF="http://net.doit.wisc.edu/~plonka/Net-Patricia/">http://net.doit.wisc.edu/~plonka/Net-Patricia/</A>
</PRE>

<P>

<LI><STRONG><A NAME="item_Cflow">Cflow

</A></STRONG>
This perl module is used by FlowScan to read the raw flow files written by
cflowd. It is available at:


<P>

<PRE>   <A HREF="http://net.doit.wisc.edu/~plonka/Cflow/">http://net.doit.wisc.edu/~plonka/Cflow/</A>
</PRE>

<P>

You'll need Cflow-1.024 or greater.


<P>

<LI><STRONG><A NAME="item_FlowScan">FlowScan

</A></STRONG>
This package is available at:


<P>

<PRE>   <A HREF="http://net.doit.wisc.edu/~plonka/FlowScan/">http://net.doit.wisc.edu/~plonka/FlowScan/</A>
</PRE>

<P>

</UL>
</UL>
<P>
<HR>
<H1><A NAME="Configuring_FlowScan_Prerequisit">Configuring FlowScan Prerequisites

</A></H1>
<P>
<HR>
<H2><A NAME="Choose_a_User_to_Run_cflowd_and_">Choose a User to Run cflowd and FlowScan

</A></H2>
I recommend that you create a user just for the purpose of running these
utilities so that all directory permissions and created file permissions
are consistent. You may find this useful especially if you have multiple
network engineers accessing the flows.


<P>

I suggest that the FlowScan <CODE>--prefix</CODE> directory be owned by an appropriate user and group, and that the
permissions allow write by other members of the group. Also, turn on the
set-group-id bit on the directory so that newly created files (such as the
flow files and log file) will be owned by that group as well, e.g.:


<P>

<PRE>   user$ chmod g+ws $PREFIX
</PRE>

<P>

<P>
<HR>
<H2><A NAME="Configuring_Your_Host">Configuring Your Host

</A></H2>
The current FlowScan graphing stuff likes your machine to have the
<CODE>80/tcp</CODE> service to be called <CODE>http</CODE>. Try running this command:


<P>

<PRE>   $ perl -le &quot;print scalar(getservbyport(80, 'tcp'))&quot;
</PRE>

<P>

You can continue with the next step if this command prints <CODE>http</CODE>. However, if it prints some other value, such as <CODE>www</CODE>, then I suggest you modify your <EM>/etc/services</EM> file so that the line containing
<CODE>80/tcp</CODE> looks something like this:


<P>

<PRE>   http             80/tcp    www www-http         #World Wide Web HTTP
</PRE>

<P>

Be sure to leave the old name such as <CODE>www</CODE> as an ``alias'', like I've shown here. This will reduce the risk of
breaking existing applications which may refer to the service by that name.
If you decide not to modify the service name in this way, FlowScan should
still work, but you'll be on your own when it comes to producing graphs.


<P>

<P>
<HR>
<H2><A NAME="Configuring_Your_Ciscos">Configuring Your Ciscos

</A></H2>
First and foremost, to get useful flow information from your Cisco, you'll
need to enable flow-switching on the appropriate ingress interfaces using
this interface-level configuration statement:


<P>

<PRE>   ip route-cache flow
</PRE>

<P>

Also, I suggest that you export from your Cisco like this:


<P>

<PRE>   ip flow-export version 5 peer-as
   ip flow-export destination 10.0.0.1 2055
</PRE>

<P>

Of course the IP address and port are determined by your
<EM>cflowd.conf</EM>. To help ensure that flows are exported in a timely fashion, I suggest you
also do this if your IOS version supports it:


<P>

<PRE>   ip flow-cache timeout active 1
</PRE>

<P>

Some IOS versions, e.g. 12.0(9), use this syntax instead:


<P>

<PRE>   ip flow-cache active-timeout 1
</PRE>

<P>

unless you've specified something such as <CODE>downward-compatible-config 11.2</CODE>.


<P>

Lastly, in complicated environments, choosing which particular interfaces
should have <CODE>ip route-cache flow</CODE> enabled is somewhat difficult. For FlowScan, one usually wants it enabled
for any interface that is an ingress point for traffic that is from inside
to outside or vice-versa. You probably don't want flow-switching enabled
for interfaces that carry policy-routed traffic, such as that being
redirected transparently to a web cache. Otherwise, FlowScan could count
the same traffic twice because of multiple flows being reported for what
was essentially the same traffic making multiple passes through a border
router. E.g. user-to-webcache, webcache-to-outside world (on behalf of that
user).


<P>

<P>
<HR>
<H2><A NAME="Configuring_cflowd">Configuring cflowd

</A></H2>
This document does not attempt to explain cflowd. There is good
documentation provided with that package.


<P>

As for the tweaks necessary to get cflowd to play well with FlowScan,
hopefully, an example is worth a thousand words.


<P>

My <EM>cflowd.conf</EM> file looks like this:


<P>

<PRE>   OPTIONS {
     LOGFACILITY:          local6
     TCPCOLLECTPORT:       2056
     TABLESOCKFILE:        /home/whomever/cflowd/etc/cflowdtable.socket
     FLOWDIR:              /var/local/flows
     FLOWFILELEN:          1000000
     NUMFLOWFILES:         10
     MINLOGMISSED:         300
   }
   CISCOEXPORTER {
     HOST:         10.0.0.10
     ADDRESSES:    { 10.42.42.10,
                   }
     CFDATAPORT:   2055
   #  COLLECT:      { flows }
   }
   COLLECTOR {
     HOST:         127.0.0.1
     AUTH:         none
   }
</PRE>

<P>

And I invoke the <EM>patched</EM> cflowd like this:


<P>

<PRE>   user$ cflowd -s 300 -O 0 -m /path/to/cflowd.conf
</PRE>

<P>

Those options cause a flow file to be ``dropped'' every 5 minutes, skipping
flows with an output interface of zero unless they are multicast flows.
Once you have this working, your ready to continue.


<P>

<P>
<HR>
<H1><A NAME="Configuring_FlowScan">Configuring FlowScan

</A></H1>
<P>
<HR>
<H2><A NAME="Configure_and_Install">Configure and Install

</A></H2>
<STRONG>Do not</STRONG> use the same <CODE>--prefix</CODE> value as might for other packages!


<P>

I.e. don't use <EM>/usr/local</EM> or a similar directory in which other things are installed. This prefix
should be the directory where the patched cflowd has been configured to
write flow files.


<P>

A good way to avoid doing something dumb here is to not run FlowScan's
<CODE>configure</CODE> nor <CODE>make</CODE> as root.


<P>

<PRE>   user$ ./configure --help # note --with-... options
</PRE>

<P>

e.g.:


<P>

<PRE>   user$ ./configure --prefix=/var/local/flows
   user$ make
   user$ make -n install
   user$ make install
</PRE>

<P>

By the way, in the above commands, all is OK if make says ``<CODE>Nothing to
be done for `target'</CODE>''. As long as <CODE>make</CODE> completes without an error, all is OK.


<P>

Subsequently in this document the ``prefix'' directory will be referred to
as the ``<CODE>--prefix</CODE> diretory'' or using the environment variable
<CODE>$PREFIX</CODE>. FlowScan does not require or use this environment variable, it's just a
documentation convention so you know to use the directory which you passed
as with <CODE>--prefix</CODE>.


<P>

<P>
<HR>
<H2><A NAME="Create_the_Output_Directory">Create the Output Directory

</A></H2>
The <CODE>OutputDir</CODE> is where the <CODE>.rrd</CODE> files and graphs will reside. As the chosen FlowScan user do:


<P>

<PRE>  $ PREFIX=/var/local/flows
  $ mkdir -p $PREFIX/graphs
</PRE>

<P>

Then, when you edit the <CODE>.cf</CODE> files below, be sure to specify this using the <CODE>OutputDir</CODE> directive.


<P>

<P>
<HR>
<H2><A NAME="FlowScan_Configuration_Files">FlowScan Configuration Files

</A></H2>
The FlowScan Package ships with sample configuration files in the <CODE>cf</CODE>
sub-directory of the distribution. During initial configuration you will
copy and sometimes modify these sample files to match your network
environent and your purposes.


<P>

FlowScan looks for its configuration files in its <CODE>bin</CODE> directory - i.e. the directory in which the <CODE>flowscan</CODE> perl script <EM>and</EM> FlowScan report modules are installed. I don't really like this, but that's
the way it is for now. Forgive me.


<P>

FlowScan currently uses two kinds of cofiguration files:


<P>

<OL>
<LI><STRONG><A NAME="item_Directive_style_configuration_fi"> Directive-style configuration files, with the .cf extension

</A></STRONG>
This format should be relatively self-explanatory based on the sample files
referenced below. The directives are documented in comments within those
sample configuration files.


<P>

A number of the directorives have paths to directory entries as their
values. One has a choice of configuring these as either relative or
absolute paths. The samples configuration files ship with relative path
specifications to minimize the changes a new user must make. However, in
this configuration, it is imperitive that <CODE>flowscan</CODE> be run in the <CODE>--prefix</CODE> directory if these relative paths are used.


<P>

<LI><STRONG><A NAME="item__Boulder_IO_format_files_with_"> "Boulder IO" format files, with the .boulder extension

</A></STRONG>
I've chosen Boulder IO's ``semantic free data interchange format'' to use
for related projects, and since this is the format in which our subnet
definitions were available, I continued to use it.


<P>

If you're new to ``Boulder IO'', the examples referenced below should be
sufficient. Remember that lines containing just <CODE>=</CODE> are record seperators.


<P>

For complete information on this format, do:


<P>

<PRE>   $ perldoc Boulder # or &quot;perldoc bolder&quot; if that fails
</PRE>

<P>

</OL>
Here's a step-by-step guide to installing, reviewing, and editing the
FlowScan configuration files:


<P>

<UL>
<LI><STRONG><A NAME="item_Copy">Copy and Edit flowscan.cf

</A></STRONG>
<PRE>  $ cp cf/flowscan.cf $PREFIX/bin
  $ chmod u+w $PREFIX/bin/flowscan.cf
  $ # edit $PREFIX/bin/flowscan.cf
</PRE>

<P>

<LI><STRONG><A NAME="item_Decide">Decide which FlowScan Reports to Run

</A></STRONG>
The FlowScan package contains the <CODE>CampusIO</CODE> and <CODE>SubNetIO</CODE> reports. These two reports are mutually exclusive - <CODE>SubNetIO</CODE> does everything that <CODE>CampusIO</CODE> does, and more.


<P>

Initially, in <EM>flowscan.cf</EM> I strongly suggest you configure:


<P>

<PRE>   ReportClasses CampusIO
</PRE>

<P>

rather than:


<P>

<PRE>   ReportClasses SubNetIO
</PRE>

<P>

The <CODE>CampusIO</CODE> report class is simpler than <CODE>SubNetIO</CODE>, requires less configuration, and is less CPU/processing intensive. Once
you have the
<CODE>CampusIO</CODE> stuff working, you can always go back and configure
<CODE>flowscan</CODE> to use <CODE>SubNetIO</CODE> instead.


<P>

There is POD documentation provided with the <CODE>CampusIO</CODE> and
<CODE>SubNetIO</CODE> reports. Please use that as the definitive reference on configuration
options for those reports, e.g.:


<P>

<PRE>   $ cd bin
   $ perldoc CampusIO
</PRE>

<P>

<LI><STRONG><A NAME="item_Copy">Copy and Edit CampusIO.cf

</A></STRONG>
Copy the template to the <EM>bin</EM> directory. Adjust the values using the required and optional configuration
directives documented there-in.


<P>

The most important thing to consider configuring in <EM>CampusIO.cf</EM> is the method by which <CODE>CampusIO</CODE> should identify outbound flows. In order of preference, you should define <CODE>NextHops</CODE>, or
<CODE>OutputIfIndexes</CODE>, or neither. Beware that if you define neither, CampusIO will resort to
using the flow destination address to determine whether or not the flow is
outbound. This can be troublesome if you do not accurately define your
local networks (below), since flows forwarded to any non-local addresses
will be considered outbound. If possible, it's best to define the list of <CODE>NextHops</CODE> to which you know your outbound traffic is forwarded.


<P>

For most purposes, the default values for the rest of the <CODE>CampusIO</CODE>
directives should suffice. For advanced users that export from multiple
Ciscos to the same cflowd/FlowScan machine, it is also very important to
configure <CODE>LocalNextHops</CODE>.


<P>

<LI><STRONG><A NAME="item_Copy">Copy and Edit local_nets.boulder

</A></STRONG>
Copy the template to the <EM>bin</EM> directory. This file should be referenced in <EM>CampusIO.cf</EM> by the <CODE>LocalSubnetFiles</CODE> directive.


<P>

The <EM>local_nets.boulder</EM> file must contain a list of the networks or subnets within your
organization. It is imperative that this file is maintained accurately
since flowscan will use this to determine whether a given flow represents
inbound traffic.


<P>

You should probably specify the networks/subnets in as terse a way as
possible. That is, if you have two adjacent subnets that can be coallesced
into one specification, do so. (This is differnet than the similarly
formatted <EM>our_subnets.boulder</EM> file mentioned below.)


<P>

The format of an entry is:


<P>

<PRE>   SUBNET=10.0.0.0/8
   [TAG=value]
   [...]
</PRE>

<P>

Technically, <CODE>SUBNET</CODE> is the only tag required in each record. You may find it useful to add
other tags such as <CODE>DESCRIPTION</CODE> for documentation purposes. Entries are seperated by a line containing a
single <CODE>=</CODE>.


<P>

FlowScan identifies outbound flows based on the list of nexthop addresses
that you'll set up below.


<P>

<LI><STRONG><A NAME="item_Copy">Copy and Edit Napster_subnets.boulder (if referenced in CampusIO.cf)

</A></STRONG>
Note: if you do not wish to have <CODE>CampusIO</CODE> attempt to identify Napster traffic, be sure to comment out all Napster
related option in
<EM>CampusIO.cf</EM>.


<P>

Copy the template to the <EM>bin</EM> directory from which you will be running <CODE>flowscan</CODE>. The supplied content seems to work well as of this writing (Mar 10,
2000). No warranties. Please let me know if you have updates regarding
Napster IP address usage, protocol, and/or port usage.


<P>

The file <EM>Napster_subnets.boulder</EM> should contain a list of the networks/subnets in use by Napster, i.e. <CODE>napster.com</CODE>.


<P>

As of this writing, more info on Napster can be found at:


<P>

<PRE>   <A HREF="http://napster.cjb.net/">http://napster.cjb.net/</A>
   <A HREF="http://opennap.sourceforge.net/napster.txt">http://opennap.sourceforge.net/napster.txt</A>
   <A HREF="http://david.weekly.org/code/napster-proxy.php3">http://david.weekly.org/code/napster-proxy.php3</A>
</PRE>

<P>

<LI><STRONG><A NAME="item_Copy">Copy and Edit SubNetIO.cf (if you have selected it in your ReportClasses)

</A></STRONG>
Copy the template to the <EM>bin</EM> directory from which you will be running flowscan. Adjust the values using
the required and optional configuration directives documented there-in. For
most purposes, the default values should suffice.


<P>

<LI><STRONG><A NAME="item_Copy">Copy and Edit our_subnets.boulder (if you use ReportClasses SubNetIO)

</A></STRONG>
Copy the template to the <EM>bin</EM> directory.


<P>

This file is used by the <CODE>SubNetIO</CODE> report class, and therefore is only necessary if you have defined <CODE>ReportClasses SubNetIO</CODE> rather than <CODE>ReportClasses CampusIO</CODE>.


<P>

The file <EM>our_subnets.boulder</EM> should contain a list of the subnets on which you'd like to gather I/O
statistics.


<P>

You should format this file like the aforementioned
<EM>local_nets.boulder</EM> file. However, the <CODE>SUBNET</CODE> tags and values in this file should be listed exactly as you use them in
your network: one record for each subnet. So, if you have two subnets, with
different purposes, they should have seperate entries even if they are
numerically adjacent. This will enable you to report on each of those user
populations independently. For instance:


<P>

<PRE>   SUBNET=10.0.1.0/24
   DESCRIPTION=power user subnet
   =
   SUBNET=10.0.2.0/24
   DESCRIPTION=luser subnet
</PRE>

<P>

</UL>
<P>
<HR>
<H2><A NAME="Preserving_Old_Flow_Files">Preserving "Old" Flow Files

</A></H2>
If you'd like to have FlowScan save your flow files, make a sub-directory
named <EM>saved</EM> in the directory where flowscan has been configured to look for flow files.
This has been specified with the
<CODE>FlowFileGlob</CODE> directive in <EM>flowscan.cf</EM> and is usually the same directory that is specified using the <CODE>FLOWDIR</CODE> directive in your
<EM>cflowd.conf</EM>.


<P>

If you do this, flowscan will move each flow file to that <EM>saved</EM>
sub-directory after processing it. (Otherwise it would simply remove them.)
e.g.:


<P>

<PRE>   $ mkdir $PREFIX/saved
   $ touch $PREFIX/saved/.gzip_lock
</PRE>

<P>

The <EM>.gzip_lock</EM> file created by this command is used as a lock file to ensure that only one
cron job at a time.


<P>

Be sure to set up a crontab entry as is mentioned below in <A HREF="#Final_Setup">Final Setup</A>. I.e. don't complain to the author if you're saving flows and your
file-system fills up ;^).


<P>

<P>
<HR>
<H1><A NAME="Testing_FlowScan">Testing FlowScan

</A></H1>
Once you have the patched cflowd running with the <CODE>-s 300</CODE> option, and it has written at least one time-stamped flow file (i.e. other
than
<EM>flows.current</EM>), try this:


<P>

<PRE>  $ cd /dir/containing/your/time-stamped/raw/flow/files
  $ flowscan
</PRE>

<P>

The output should appear as something like this:


<P>

<PRE>   Loading &quot;bin/Napster_subnets.boulder&quot; ...
   Loading &quot;bin/local_nets.boulder&quot; ...
   2000/03/20 17:01:04 working on file flows.20000320_16:57:22...
   2000/03/20 17:07:38 flowscan-1.013 CampusIO: Cflow::find took 394 wallclock secs (350.03 usr +  0.52 sys = 350.55 CPU) for 23610455 flow file bytes, flow hit ratio: 254413/429281
   2000/03/20 17:07:41 flowscan-1.013 CampusIO: report took  3 wallclock secs ( 0.44 usr +  0.04 sys =  0.48 CPU)
   sleep 300...
</PRE>

<P>

At this point, the RRD files have been created and updated as the flow
files are processed. If not, you should use the diagnostic warning and
error messages or the perl debugger (<CODE>perl -d flowscan</CODE>) to determine what is wrong.


<P>

Look at the above output carefully. It is imperative that the number of
seconds that <CODE>Cflow::find took</CODE> not usually approach nor exceed 300. If, as in the example above, your log
messages indicate that it took more than 300 seconds, FlowScan will not be
able to keep up with the flows being collected on this machine (if the
given flow file is representative). If the total of usr + sys CPU seconds
totals more than 300 seconds, than this machine is not even capable of
running FlowScan fast enough, and you'll need to run it on a faster machine
(or tweak the code, rewrite in C, or mess with process priorities using
<CODE>nice(1),</CODE> etc.)


<P>

<P>
<HR>
<H1><A NAME="Performance_Problems_">Performance Problems?

</A></H1>
Here are some hints on getting the most out of your hardware if you find
that FlowScan is processing 300 seconds of flows in less an averave of 300
CPU seconds or less, but not 300 seconds of real time; i.e. the <CODE>flowscan</CODE> process is not being scheduled to run often enough because of context
switching or because of its competing for CPU with too many other
processes.


<P>

On a 2 processor Intell PIII, to keep <CODE>flowscan</CODE> from having to compete with other processes for CPU, I have recently had
good luck with setting the <CODE>flowscan</CODE> process' <CODE>nice(1)</CODE> value to -20.


<P>

Furthermore, I applied this experimental patch to the Linux 2.2.18pre21
kernel:


<P>

<PRE>   <A HREF="http://isunix.it.ilstu.edu/~thockin/pset/">http://isunix.it.ilstu.edu/~thockin/pset/</A>
</PRE>

<P>

This patch enables users to determine which processor or set of processors
a process may run on. Once applied, you can reserve the 2nd processor
solely for use by <CODE>flowscan</CODE>:


<P>

<PRE>   root# mpadmin -r 1
</PRE>

<P>

Then launch <CODE>flowscan</CODE> on processor number 1:


<P>

<PRE>   root# /usr/bin/nice --20 /usr/bin/runon 1 /usr/bin/su - username -c '/usr/bin/nohup /var/local/flows/bin/flowscan -v' &gt;&gt; /var/local/flows/flowscan.log 2&gt;&amp;1 &lt;/dev/null &amp;'
</PRE>

<P>

This configuration has yielded the best ratio of CPU to real seconds that I
have seen - nearly 1 to 1.


<P>

<P>
<HR>
<H1><A NAME="Final_Setup">Final Setup

</A></H1>
Once you feel that <CODE>flowscan</CODE> is working correctly, you can set it (and <CODE>cflowd</CODE>) to start up at system boot time. Sample <CODE>rc</CODE> scripts for Solaris and Linux are supplied in the <EM>rc</EM> sub-directory of this distribution. You may have to edit these scripts
depending on your <CODE>ps(1)</CODE> flavor and where various commands have
been installed on your system.


<P>

Also, if you're saving your flow files, you should set up crontab entries
to handle the ``old'' flows. I use one crontab entry to
<CODE>gzip(1)</CODE> recently processed files, and another to delete the files older than a
given number of hours. The ``right'' number of hours is a function of your
file-system size and the rate of flows being exported/collected. See the <EM>example/crontab</EM> file.


<P>

<P>
<HR>
<H1><A NAME="Generating_Graphs">Generating Graphs

</A></H1>
<P>
<HR>
<H2><A NAME="Supplied_Graphs">Supplied Graphs

</A></H2>
To generate graphs, try the <EM>graphs.mf</EM> Makefile:


<P>

<PRE>  $ cp graphs.mf $PREFIX/graphs/Makefile
  $ cd $PREFIX/graphs
  $ make
</PRE>

<P>

This should produce the ``Campus I/O by IP Protocol'' and ``Well Known
Services'' graphs in PNG files. GIF files may be produced using the
<CODE>filetype</CODE> option mentioned below.


<P>

If this command fails to produce those graphs, it is likely that some of
the requisite <CODE>.rrd</CODE> files are missing, i.e. they have not yet been created by FlowScan, such as <EM>http_dst.rrd</EM>. If this is the case, it is probably because you skipped the configuration
of <EM>/etc/services</EM>
in <A HREF="#Configuring_Your_Host">Configuring Your Host</A>. Stop <CODE>flowscan</CODE>, rename your
<EM>www_*.rrd</EM> files to <EM>http_*.rrd</EM>, modify <EM>/etc/services</EM>, and restart <CODE>flowscan</CODE>.


<P>

Alternatively, you may copy and customize the <EM>graphs.mf</EM> Makefile to remove references to the missing or misnamed <CODE>.rrd</CODE> files for those targets. Also, you could produce your graphs using a
graphing tool such as RRGrapher mentioned below in <A HREF="#Custom_Graphs">Custom Graphs</A>.


<P>

Note that the <EM>graphs.mf</EM> template Makefile has options to specify such things as the range of time,
graph height and width, and output file type. Usage:


<P>

<PRE>   make -f graphs.mf [filetype=&lt;png|gif&gt;] [width=x] [height=y] [ioheight=y+n] [hours=h] [tag=_tagval] [events=public_events.txt] [organization='Foobar U - Springfield Campus']
</PRE>

<P>

as in:


<P>

<PRE>   $ make -f graphs.mf filetype=gif height=400 hours=24 io_services_bits.gif
</PRE>

<P>

<P>
<HR>
<H2><A NAME="Adding_Events_to_Graphs">Adding Events to Graphs

</A></H2>
There is a new graphing feature which allows you to specify events that
should be displayed in your graphs. These events are simply a list of
points in time at which something of interest occurred.


<P>

For instance, one could create a plain text file in the <EM>graphs</EM>
directory called <EM>events.txt</EM> containing these lines:


<P>

<PRE>   2001/02/10 1538 added support for events to FlowScan graphs
   2001/02/12 1601 allowed the events file to be named on make command line
</PRE>

<P>

Then to generate the graphs with those events included one might run:


<P>

<PRE>   $ make -f graphs.mf events=events.txt
</PRE>

<P>

This feature was implemented using a new script called <EM>event2vrule</EM>
that is supplied with FlowScan. This script is meant to be used as a
``wrapper'' for running <CODE>rrdtool(1),</CODE> similarly to how one might
run <CODE>nohup(1).</CODE> E.g.:


<P>

<PRE>   $ event2vrule -h 48 events.txt rrdtool graph -s -48h ...
</PRE>

<P>

That command will cause these <CODE>VRULE</CODE> arguments to be passed to rrdtool, at the end of the argument list:


<P>

<PRE>   COMMENT:\n
   VRULE:981841080#ff0000:2001/02/10 1538 added support for events to FlowScan graphs
   COMMENT:\n
   VRULE:982015260#ff0000:2001/02/12 1601 allowed the events file to be named on make command line
   COMMENT:\n
</PRE>

<P>

<P>
<HR>
<H2><A NAME="Custom_Graphs">Custom Graphs

</A></H2>
Creation of other graphs will require the use of a tool such as RRGrapher
or knowledge of RRDTOOL. RRGrapher, my Graph Construction Set for RRDTOOL
is available at:


<P>

<PRE>   <A HREF="http://net.doit.wisc.edu/~plonka/RRGrapher/">http://net.doit.wisc.edu/~plonka/RRGrapher/</A>
</PRE>

<P>

For other custom graphs, if you use the supplied <EM>graphs.mf</EM> Makefile, you can use the examples there in to see how to build ``Campus
I/O by Network'' and ``AS to AS'' graphs. The examples use UW-Madison
network numbers, names of with which we peer and such, so it will be
non-trivial for you to customize them, but at least there's an example.


<P>

Currently, RRD files for the configured <CODE>ASPairs</CODE> contain a <CODE>:</CODE> in the file name. This is apparently a no-no with RRDTOOL since, although
it allows you create files with these names, it doesn't let you graphs
using them because of how the API uses <CODE>:</CODE> to seperate arguments.


<P>

For the time being, if you want to graph AS information, you must manually
create symbolic links in your graphs sub-dir. i.e.


<P>

<PRE>   $ cd graphs
   $ ln -s 0:42.rrd Us2Them.rrd
   $ ln -s 42:0.rrd Them2Us.rrd
</PRE>

<P>

A reminder for me to fix this is in the <EM>TODO</EM> list.


<P>

<P>
<HR>
<H2><A NAME="Future_Directions_for_Graphs">Future Directions for Graphs

</A></H2>
The current Makefile-based graphing, while coherent, is cumbersome at best.
I find that the verbosity and complexity of adding new graph targets to the
Makefile makes my brain hurt.


<P>

Other RRDTOOL front-ends that produce graphs should be able to work with
FlowScan-generated <CODE>.rrd</CODE> files, so there's hope.


<P>

<P>
<HR>
<H1><A NAME="Copyright_and_Disclaimer">Copyright and Disclaimer

</A></H1>
Note that this document is provided `as is'. The information in it is not
warranted to be correct. Use it at your own risk.


<P>

<PRE>   Copyright (c) 2000-2001 Dave Plonka &lt;plonka@doit.wisc.edu&gt;.
   All rights reserved.
</PRE>

<P>

This document may be reproduced and distributed in its entirety (including
this authorship, copyright, and permission notice), provided that no charge
is made for the document itself.


<P>


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