nanog mailing list archives

Re: DDoS attacks


From: Brad <brad () americanisp net>
Date: Thu, 12 Jul 2001 09:55:48 -0600 (MDT)


On Thu, 12 Jul 2001 up () 3 am wrote:

On Thu, 12 Jul 2001, Brad wrote:

Here are my thoughts on DDoS:

-The problem should not be addressed by going after the
originators of the attacks, rather a real-time targeting
system for those 'compromised' client computers with zombies

I think this approach, while helpful, isn't going to solve anything.  I
seem to recall an RBL of sorts (Denninger?) for networks that had routers
that allowed directed broadcasts, and thus smurf attacks.  Cisco also
(finally) put it in their default config.

Thanks for the post James.

Well- I think we are dealing with different issues which
seem to change things a bit..  Putting in 'no ip
directed-broadcast' in a cisco interface is a one-time quick
and easy fix for all of those problems.  Therefore- calling
the admin of a network who is allowing directed broadcasts,
and even helping them to fix it for good, has been a good
and easy task.  However, the problem here is not-so easy to
take care of on the provider(s) end.  I tend to see this
problem more-like open-relay issues.  A open-relay SMTP
server is just-as much a pain in the rear as a compromised
windoze box (if not more) and we have several ways to combat
open-relay issues currently through various testing and
filtering systems.

Problem solved?  Well, smurf attacks are down, but DDoS attacks are way
up.  Why?  Well, you can put a big part of the blame on M$, but my guess
is that many of the same perpetrators of those smurf attacks are now
operating these bots.  I can't help but believe that if even 20% of them
were caught and had to spend just a little time (even hours) with the
cops, and had their peecees confiscated, you'd not be seeing nearly the
problems we are now.

I would agree that if we actually caught and punished the
attackers, the number of attacks would go down..  But there
are a lot of issues with doing that.  You have to wait till
the attacker actually takes down and causes $$ damages to
your network/company prior to even being looked at by a
court.  In this industry, many companies may not survive
long if such an attack took place, and would most likely not
be able to front attorney fees to go after a 15-year old who
could questionably be tried and punished after the fact.

Yes, going after vulnerabilities are good, but you'll never get them all.
If you were to go after the source of the attacks, and just got enough to
demonstrate that this is a much riskier activity than it is now, I think
it would be much more effective.

I like your feedback. Maybe we can do both :)

7-11's aren't built like banks, but those cameras (and tanacious
investigations) have drastically reduced holdups.

I dont know ;)  They both have non-removable time-lock
safes, security systems, cameras, magnetic-locking doors,
panic-buttons, etc, etc...  :)

James Smallacombe                   PlantageNet, Inc. CEO and Janitor
up () 3 am                                                        http://3.am


---
Brad Baker
Director: Network Operations
American ISP
brad () americanisp net
+1 303 984 5700 x12
http://www.americanisp.net/


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