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Randy Bradley wrote:
> 
> On Aug 21, 2006, at 11:47 PM, gentuxx wrote:
> 
>> Obviously, I'm trying to understand how the hierarchy works here (in
>>
>> addition to monitoring my systems).
>>
> 
> 
>    I, too, would like to understand the rules better.  I am collecting
> my router logs to my Mac server.  I have set up my local rules.xml file
> and used the syslog log format option.  
> 
>    I made the assumption that the rules would be tested in a top down
> fashion but experimentation leads me to believe that the rule with the
> highest "level" will be the one matched.  Is this true or am I all wet here?
> 

This is true.  Rules with the highest level are matched first.  It'
still a bit sparse at the moment, but take a look at
http://www.ossec.net/wiki/index.php/Know_How:Rules_Severity for more info.

>   Other questions:
> 
>    Are there more details of the regex library used?  In particular, the
> "(" and ")" characters.  "\(80\)" seems to find the (80) string in my
> log files, however, "\(\d+\)" doesn't seem to match anything.  I see
> some of the rules shipped put the \d+ inside brackets, ex [\d+].  Are
> the brackets required?

The "()" characters are "grouping and capture" characters.  So, given
something like the following:

<regex>^\d+ (\d+.\d+.\d+.\d+) (\w+)/(\d+) \d+ \w+ (\S+) </regex>

...the first parentheses would capture four groups of digits separated
by dots (or an IP address).  Check out
http://www.ossec.net/wiki/index.php/Know_How:Regex_Readme for more
details on the regular expressions used.

> 
>    What is "accuracy"?  The descriptions simply says 0 or 1.  What is it
> used for?

Not really sure about this one.  But I read somewhere (source or manual)
that it indicates whether a rule is accurate or not.  The part I'm not
sure about is how the program responds if it's specified as accurate or
inaccurate.

> 
>    What is a Monolithic rules file?  Meir has great instructions on how
> to create one.  Is it simply a compiled file made from all of the rule
> files?  Seems like a good idea for a production system but a lot of
> bother for a system used for rule development.
> 

I believe this is just a way to have all of your rules in one file.
It's still XML/text, but is all contained in one file ass opposed to
being split up.  Being a long time snort user, I, personally, am
accustomed to having the rules split up and don't see the value in
having one file.

> 
> Thanks Daniel and everyone else for
> all of your hard work on this project.
> 
> 
> Randy


- --
gentux
echo "hfouvyyAhnbjm/dpn" | perl -pe 's/(.)/chr(ord($1)-1)/ge'

gentux's gpg fingerprint ==> 5495 0388 67FF 0B89 1239  D840 4CF0 39E2
18D3 4A9E
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iD8DBQFE6zZ6TPA54hjTSp4RAmt5AKCyf0mj1lngWKnf9Am/UaH/S1/5OwCeJzrj
emq0J0dVeHGB8CSAbCXKcAs=
=2sxE
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