# [solved] Dynamic Preprocessor error when starting snort.

## mallytheelder

I followed this guide to install snort on my gentoo box.  When I try and start snort I get the following error.

 "FATAL ERROR: /etc/snort/snort.conf(197) => Unknown rule type: dynamicpreprocessor"

I have tried doing searches on the net and the forums, but haven't come up with any answers.  Any help would be appreciated.

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## und3ad

I get the exact same error, and no clues as to why.. Googling gives no answers either.

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## und3ad

I found out why by accident.. Enable the dynamicplugin USE flag and all should be fine.  :Smile: 

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## mikegpitt

Same issue here, but the solution no longer works.

After re-emerging snort with the dynamicplugin use flag I get this in my logs:

```
Loading dynamic engine /usr/local/lib/snort_dynamicengine/libsf_engine.so... 

FATAL ERROR: Failed to load /usr/local/lib/snort_dynamicengine/libsf_engine.so: /usr/local/lib/snort_dynamicengine/libsf_engine.so: cannot open shared object file: No such file or directory
```

Of coruse it can't find it, because it is lookign int he wrong place /usr/local, instead of /usr.

Anyone have and ideas what to change?  This is annoying for 2 reasons, 1) this error, and 2) why does the default config point to things that need to be enabled via other use flags?

EDIT: The /usr/local was commign from the snort.conf file, got rid of them and thigns worked well.

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## mikegpitt

I made a bug report for this issue if anyone cares:

https://bugs.gentoo.org/show_bug.cgi?id=166874

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## binaural

Fixed!

```
cd /usr/local/lib && ln -s /usr/lib/snort_dynamicengine snort_dynamicengine && ln -s /usr/lib/snort_dynamicpreprocessor snort_dynamicpreprocessor
```

You note it in the bug report, but that's how it's done with one line of code...

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## mikegpitt

I'm glad to se the report benefited someone   :Smile: 

 *binaural wrote:*   

> Fixed!
> 
> ```
> cd /usr/local/lib && ln -s /usr/lib/snort_dynamicengine snort_dynamicengine && ln -s /usr/lib/snort_dynamicpreprocessor snort_dynamicpreprocessor
> ```
> ...

 

This solution is a little unclean, since it leaves the entries in /usr/local, and isn't indexed in portage.  If you edit the config then snort looks in the correct place.

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## binaural

 *mikegpitt wrote:*   

> I'm glad to se the report benefited someone  :) 
> 
>  *binaural wrote:*   Fixed!
> 
> ```
> ...

 

Agreed.

How bout this:

```
perl -pi -e 's/\/local\//\//g' /path/to/snort.conf
```

? 

Now that I have snort and base installed I have to figoure out what I'm supposed to do with it... ;)

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## mikegpitt

BTW -  The bug is being addressed for the snort-2.6.1.3-r1 release comming soon:

https://bugs.gentoo.org/show_bug.cgi?id=166874

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## keddie

on my server snort start working after uncommenting that line in the /etc/snort/snort.conf file:

dynamicpreprocessor directory /usr/lib/snort/dynamicpreprocessor

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