[c-nsp] Large networks

[Gert Doering]

Hi,

On Tue, Aug 25, 2009 at 08:58:32PM -0400, Steve Bertrand wrote:
> > This company was constantly having problems with what i called broadcast
> > attacks.  The network graphs would show traffic on all interfaces spike
> > and normally the 100mbit uplink between the switches would saturate and
> > the network would die.  From that experience i took my time to design
> > and deploy my network to be as correct as possible. 
> 
> Out of curiosity, did your experience find that the issues were related
> to actual broadcast problems?

Generally, putting each customer into a dedicated layer 3 network segment
is a good idea - because half of the attacks that a hacked server belonging
to "customer 1" might do to a server from "customer 2" (ARP spoofing, 
IP address spoofing [-> blaim goes to customer 2], HSRP attacks to the
shared router, etc.) suddenly are no longer relevant at all.

... and *if* you need to ACL one customer, or just shut down their 
network segment (because they are busy attacking someone else), you
can be sure that it doesn't affect other customers ;-)

gert
-- 
USENET is *not* the non-clickable part of WWW!
                                                           //www.muc.de/~gert/
Gert Doering - Munich, Germany                             gert at greenie.muc.de
fax: +49-89-35655025                        gert at net.informatik.tu-muenchen.de
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