Techniques for passive traffic capturing

Matt Cable wozz at
Wed Jun 25 16:47:50 CDT 2008

Ross Vandegrift <ross <at>> writes:

> On Tue, Jun 24, 2008 at 01:19:03PM +1200, Nathan Ward wrote:
> > I see little point in aggregating tapped traffic, unless you have only  
> > a small amount of it and you're doing it to save cost on monitoring  
> > network interfaces - but is that saved cost still a saving when you  
> > factor in the cost of the extra 3750s in the middle? I'd guess no.
> Thanks for all the info Nathan - lots of good leads in your email.
> Let me include some more information.
> The problem is finding a way to multiplex that traffic from the
> optical tap to multiple things that want to peek at it.  The
> remote-span trick solves that, as well as integrating media
> converters.  3750 is nice since you can stack em up and mix/match the
> SFP and copper ports.
>  Taps+MultiPlexing+Filtering+Clustering+10g.  I've been
using them very successfully for exactly what you describe for the last 2 years.
 If they are a bit too pricey, look at  Similar
capabilities to Gigamon, slightly less flexibility (fixed hardware
configurations vs Gigamon's modular configuration) and possibly cheaper
depending on your needs.

More information about the NANOG mailing list