Using snort to detect if your users are doing interesting things?

Thu Jun 9 18:37:59 UTC 2005

And when you do set up such an arrangement, depending on the number of rules
you turn on, you can generate truly massive volumes of data to be analyzed
by ACID or other tools.  It is relatively easy to deploy snort for large
volume, small number of rules type deployments.  Aside from scaling the
collectors and management console themselves, it can even be a challenge to
aggregate all that data in a WAN deployment.

IDS has to be aimed carefully and then fired.  And then one needs to ask
what the derived value is, and just how you¹re going to deal with the info.
The latter being a magnificent operational challenge.

Or that¹s at least been my experience. YMMV.

On 6/9/05 1:31 PM, "Jordan Medlen" <jmedlen at sagonet.com> wrote:

> We just finished deploying a Snort IDS system on our network. The task of
> doing so was well worth the effort, and quite a bit of effort and resources
> were needed for our deployment. Due to the fact that we have a sustained 5Gbps
> of traffic to monitor in our Tampa data center alone, a simple server running
> Snort was just not going to cut it and rather than deploying off of our core
> routers in Tampa, which would catch inbound and outbound traffic, we decided
> after our testing that placing our tap points on our core routers was just not
> going to be sufficient due to the amount of abuse we saw in testing between
> customers in our facility. We decided to build a single server for each of our
> distribution switches at all of our locations that would communicate to a
> central server running the ACID console. This deployment has allowed us to
> gather so much information about what *TRULY* is and has been going on, that
> we wonder why we didn¹t do this sooner.
>  
> Please keep in mind that there are many right ways to deploy an IDS system,
> however only one is really going to fit *most* of your needs initially. With
> some time, patience, and quite a bit of caffine, you should be well on your
> way to dropping your abusive traffic on your network. Good luck to you!
>  
> --
> Jordan Medlen
> Chief Network Engineer
> Sago Networks
>  
> 
> 
> From: owner-nanog at merit.edu [mailto:owner-nanog at merit.edu] On Behalf Of Drew
> Weaver
> Sent: Thursday, June 09, 2005 11:46 AM
> To: nanog at merit.edu
> Subject: Using snort to detect if your users are doing interesting things?
>  
>            Howdy, I am not sure if this is the proper place, if not I¹ve
> noticed you guys know what to do so I¹ll put the fire retardant suit on now.
> Recently due to growth we have seen an influx of ³different² and ³interesting²
> types of characters ending up on our network. They like to do all sorts of
> things, port scan /8s spam, setup botnets with the controllers hosted on my
> network.. etc. I¹m wondering what is the best way to detect people doing these
> things on my end. I realize there are methods to protect myself from people
> attacking from the outside but I¹m not real sure how to pinpoint who is really
> being loud on the inside.
>  
> I did have one somewhat silly question.. if you look at the statistics of a
> Fast Ethernet port, and it is doing both 2000 pps out, and 2000 pps in (pretty
> much equal in/out) but hardly any bandwidth at all can anyone think of a
> single application that would mimic that behavior?
>  
> Sorry if this is elementary network school knowledge.
> -Drew
> 
> 
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> 
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