Re: parsing very large tcpdump files

[Carlos Henrique P C Chaves <cae () lac inpe br>]

Hy Tom,

i'm a brazilian msc candidate and may research is about detecting backdoors and covert channels (tunnels) analysing the 
network traffic. We have some dump files
of over than 700MB and the TCP/IP reconstructing tool takes a lot of time to do the job. When i say a lot of time, i'm 
talking about more than one day, and this
dump file is related to one hour of traffic of our institution, and we just use the header information for this. 
Imagine a full-package reconstruction. 
We are focusing on analysing C Class traffics separately, and just some protocols.

The point is: i don't think that is feasable to reconstruct such amount of traffic. I don't know
a open-source/free tool tha would do this. Maybe someone in this list can clear my mind. 

One nice step is trying to remove the noise from the dump to reduce its size.  

You can use a flow analysis tool, such as Argus, but it won't give you all the information you want.

Best regards,

Carlos Henrique. 

On Thu, Nov 18, 2004 at 06:29:32PM -0500, Tom wrote:
> moderator: sorry if this is vague.  My requirements are not fixed yet and will probably change from case to case, 
> therefore I am just looking for generic info now.
>
> I was wondering if anyone on this list can recommend some tools (Opensource or commercial) to automate the parsing of 
> very large (many GB) tcpdump files.  I am trying to put together a generic toolset but in general some things I'd 
> like to do are:
>
> 1. Filter out traffic to/from a specific IP address or range
> 2. Reconstruct all reconstructable sessions in an easy to parse way: emails, web sites visited (and content 
> uploaded/downloaded), voip, anything else imaginable.
> 3. Be able to search all of this data for keywords. 
>
> This may seem like a tall order.  I know of a few tools to do individual tasks on a small scale, such as mailsnarf, 
> vomit, ethereal,  etc. but it's not practical to use ethereal to parse these by hand. I've tried chaosreader.pl but 
> it bogs down on files as small as 200 MB.
>
> I'd appreciate any input.
>
> Thanks.
>
>
>
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