Re: Capturing network traffic and warning if its volume crosses a defined limit

[Kurth Bemis <kurth.bemis () gmail com>]

A network tap would work as well.  They are easy to make yourself.

http://www.instructables.com/id/Make-a-Passive-Network-Tap/

~k

On Fri, 2011-12-02 at 13:14 -0600, Curtis Duck wrote:
> Remember that most hubs now do not function like the hubs of the old days and may act like a switch in isolating 
> traffic. Also if there is more traffic than the port can handle there is potential to flood the port and traffic may 
> be interrupted.
>
> Curtis Duck
> AutoInc
> Systems Administrator
>
> On Dec 2, 2011, at 12:53 PM, Ali Kapucu <alikapucu () gmail com> wrote:
>
> > I recommend to use pfsense on this box. It has snort and other useful tools.
> >
> > Sent from my iPhone
> >
> > On Dec 2, 2011, at 12:34 PM, Chris Warren <chris.warren () netelligent ca> wrote:
> >
> > > With a relatively simple setup like this, it would be better to plug both the Exchange server, and your monitoring 
> > > system, into a hub.  The hub's uplink can go to the existing switch.  This way, connectivity of the Exchange 
> > > server does not depend on the monitoring system being online.
> > >
> > > However, your solution would probably be better if you want Snort to block traffic.  Snort can communicate with 
> > > some firewalls to achieve this, but probably not the typical ISP modem/router.
> > >
> > > ----- Original Message -----
> > > From: "Pranav Lal" <pranav.lal () gmail com>
> > > To: security-basics () securityfocus com
> > > Sent: Friday, December 2, 2011 12:14:43 PM
> > > Subject: Capturing network traffic and warning if its volume crosses a defined limit
> > >
> > >
> > > Hi all,
> > >
> > > A friend has been running his own Exchange 2003 enterprise server since
> > > ages. Last week, his IP address got black listed since a lot of traffic
> > > originated from his e-mail server. The ISP has blocked outbound port 25. He
> > > has checked with Microsoft support and with TrendMicro and is talking to his
> > > ISP too.  He wants something to monitor network traffic with and log
> > > traffic. I have discussed some solutions with him. What do you think?
> > > 1. For bandwidth monitoring, the only tool I know of is MRTG. There are
> > > bound to be more but they monitor and not raise alerts.
> > >
> > > 2. Yes I did suggest a firewall appliance which will solve this problem.
> > >
> > > 3. However, he is also looking for an immediate fix. This is where my
> > > current solution comes in. Before I go into the solution, let me explain his
> > > network layout.
> > >
> > > (1) The ISP's modem router's Ethernet cable is plugged into a switch. I
> > > suspect this switch is unmanaged and does not support mirroring.
> > > (2). The Exchange server is plugged into the switch.
> > > (3) I suspect the same holds true for other computers that is they are
> > > plugged into the same switch.
> > >
> > > Now for the solution
> > > A. He takes a computer with two LAN cards. Let us call them LC1 and LC2.
> > > B. His ISP router goes into LC1.
> > > C. The switch goes into LC2.
> > > D. Snort with MySQL runs on this computer and logs traffic.
> > >
> > > My questions:
> > > 1. Is there a better solution?
> > > 2. Does he need to bridge the connections corresponding to lc1 and lc2? If
> > > he does not do so, I do not see how he will get out to the Internet.
> > > 3. Can I use snort or some other application to block all network traffic if
> > > it exceeds a certain amount?
> > >
> > > Pranav
> > >
> > >
> > > ------------------------------------------------------------------------
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> > > how it benefits your company and how your customers can tell if a site is secure. You will find out how to test, 
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> > ------------------------------------------------------------------------
> > Securing Apache Web Server with thawte Digital Certificate
> > In this guide we examine the importance of Apache-SSL and who needs an SSL certificate.  We look at how SSL works, 
> > how it benefits your company and how your customers can tell if a site is secure. You will find out how to test, 
> > purchase, install and use a thawte Digital Certificate on your Apache web server. Throughout, best practices for 
> > set-up are highlighted to help you ensure efficient ongoing management of your encryption keys and digital 
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> how it benefits your company and how your customers can tell if a site is secure. You will find out how to test, 
> purchase, install and use a thawte Digital Certificate on your Apache web server. Throughout, best practices for 
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------------------------------------------------------------------------
Securing Apache Web Server with thawte Digital Certificate
In this guide we examine the importance of Apache-SSL and who needs an SSL certificate.  We look at how SSL works, how 
it benefits your company and how your customers can tell if a site is secure. You will find out how to test, purchase, 
install and use a thawte Digital Certificate on your Apache web server. Throughout, best practices for set-up are 
highlighted to help you ensure efficient ongoing management of your encryption keys and digital certificates.

http://www.dinclinx.com/Redirect.aspx?36;4175;25;1371;0;5;946;e13b6be442f727d1
------------------------------------------------------------------------