@menu
* Download ::
* Install ::
* Configuration ::
* Encrypted Reports ::
@end menu

@node Download
@section Download
@cindex download

Download Bro from: @uref{http://www.bro-ids.org/}

You can unpack the distribution anywhere except into the directory
you plan to install into. To untar the file, type:

@example
tar xvzf bro-0.9a6.6.tar.gz
@end example

@node Install
@section Install

You'll need to collect the following information before beginning the installation.

@itemize
@item localnets: a list of local subnets for your network. Bro needs to know which networks are "internal" and which are "external".

@item interface names: the names of the capture interfaces in your host (e.g. sk0 or en1). Use @code{ifconfig -a} to get the list of all network interfaces on your Bro host.
@end itemize

If you want to use Bro's periodic email report feature, you'll also need:
@itemize
@item email list: a list of email addresses to send the reports to.

@item pgp keys: if you want to encrypt all email reports, the location of the 
@uref{http://www.gnupg.org/,GPG keyring} of all recipients.
@end itemize

Bro is very easy to install. Just log in as @code{root}, and type:
@example
./configure
@end example
or to install Bro in a location other than @file{/usr/local/bro}, use:
@example
./configure --prefix=/path/to/bro
@end example
and then type:
@example
make
make install
@end example

To update an existing Bro installation with new binaries and standard policy file, instead
of @code{'make install'} do a @code{'make update'}. This will preserve all your local customizations.

@node Configuration
@section Configuration
@cindex bro_config
@cindex bro.cfg

The @emph{Bro-Lite} configuration script can be used to automatically configure Bro for you. It
checks your system's BPF settings, creates a 'bro' user account, installs
a script to start bro at boot time, and installs a number of @code{cron} jobs 
to checkpoint bro every night, run perioidic reports, and manage log files.

To run this configuration script type:
@example
make install-brolite 
@end example


This will run the script @code{bro_config}, which creates the file @file{$BROHOME/etc/bro.cfg}.
@code{bro_config} will ask a number of simple questions.

Sample output of @code{bro_config}, along with explanation, is shown below:

@quotation

@verbatim
Running Bro Configuration Utility
Checking interfaces ....  Done.
Reading /usr/local/bro/etc/bro.cfg.example for defaults.
@end verbatim
@quotation 
@quotation 
The @code{bro_config} script looks first at ./bro.cfg, then /usr/local/bro/etc,  
for default values to use below.
@end quotation
@end quotation

@verbatim
Bro Log archive location [/usr/local/bro/archive] 
@end verbatim
@quotation
@quotation
This is the directory where log file archives are kept. 
If you expect the log files to be very large, it is recommended to put these in a separate disk partition.
@end quotation
@end quotation

@verbatim
User id to install and run Bro under [bro] 
@end verbatim
@quotation
@quotation
@code{bro_config} will create a new user account with this username if the user does not exist. 
@end quotation
@end quotation

@verbatim
Interface names to listen on. [en1,en2] 
@end verbatim
@quotation
@quotation
@code{bro_config} looks for all network interfaces and does a short test to determine which interfaces see the most traffic, and selects these interfaces as the default. 
@end quotation
@end quotation

@verbatim
Site name for reports (i.e. LBNL, FOO.COM, BAZ.ORG) [] 
Starting Report Time [0600]
Report interval (in hours) [24]
Email addresses for internal reports [bro@localhost] 
Do you want to send external reports to a incident 
		reporting org (e.g.: CERT, CIAC, etc) (Y/N)
Y
Email addresses for external reports [] 
@end verbatim

@quotation
@quotation
Daily reports will be created.  
Enter the site name you want to appear at the top and in the subject of all email reports.
The 'start time' and 'interval' define the window of 
network activity that the daily report will cover, starting at 'Starting Report Time' and 
lasting through 'Report interval'. The start time should be entered using 24hr clock notation. 
For example: 12:30am = 0030,  2pm = 1400

Two types of reports will be generated,
"internal" and "external". Internal reports contain the same basic information as
the external reports, along with traffic statistics and more detailed information on 
incidents. Both internal and external reports will be sent to the "internal" email address list.
External reports are only sent if you answer "Y" and enter an external email address. 
(Note: currently only internal reports are generated)
@end quotation
@end quotation


@verbatim
Do you want to encrypt the email reports (Y/N) [N]
Y
@end verbatim
@quotation
@quotation 
If you want the email reports encrypted, you will need to set up GPG (@uref{http://www.gnupg.org})
and create a GPG keyring containing the public keys of all email recipients. Instructions 
for this are in @ref{Encrypted Reports}.

@end quotation
@end quotation

@verbatim
Running script to determine your local subnets ... 
Your Local subnets [198.129.224.1/32] 
@end verbatim
@quotation
@quotation
Bro needs to know a list of your local subnets. @code{bro_config} runs a tool 
that attempts to discover this automatically. 
You should always verify the results of this tool. The format is a list of subnet/significant 
bits of address. 
For example: 131.243.0.0/16, 198.128.0.0/18, 198.129.224.1/32
@end quotation
This information will be stored in the file @code{$BROHOME/site/local.site.bro}
@end quotation

@verbatim
Saving settings to file: /usr/local/bro/etc/bro.cfg
Bro configuration finished. 
To change these values, you can rerun bro_config at any time.
@end verbatim
@quotation
@quotation
Indicates that the script finished successfully.
@end quotation
@end quotation

@end quotation

For site monitoring very high traffic rates on Gigabit ethernet, there is some
additional system tuning that should be done. See the @uref{http://www.bro-ids.org/, Bro User Guide} for more details.


To reconfigure Bro, just type:
@example
bro_config
@end example

This will update your @file{/usr/local/bro/etc/bro.cfg} file. You can also edit this file using your favorite editor if you prefer.

For other site customizations, you can edit the file $BROHOME/site/local.site.bro.
For example, to tell bro to not look at traffic for host 198.162.44.66, add:
@verbatim
     redef restrict_filters += { ["ignore host 198.162.44.66 "] = "not (host 198.162.44.66)" };
@end verbatim

Or to disable alarms for "WeirdActivity", you can add this:
@verbatim
     redef notice_action_filters += { [[WeirdActivity]] = ignore_notice, };
@end verbatim

Any changes you make in $BROHOME/site will not be touched during an upgrade
or reinstall of Bro. You should avoid editing files in $BROHOME/policy,
as these will be overwritten.

More details are available in the Bro user guide. 

@node Encrypted Reports 
@section Encrypted Reports 
@cindex GPG

Bro can use GPG (@uref{http://www.gnupg.org/}) to encrypt
the reports that it sends. To have Bro encrypt your
reports you must have said 'yes' to the bro_config question to
encrypt your reports. For information on configuring
GPG for Bro reports, see the @uref{http://www.bro-ids.org/, Bro User Manual}.