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RE: [Full-disclosure] what can be done with botnet C&C's?


From: "Jordan Medlen" <jmedlen () sagonet com>
Date: Thu, 17 Aug 2006 11:58:16 -0400


Most major carriers have some way of communicating with them for this
purpose. Level(3) uses BGP community 9999 for a peer of theirs to issue /32
routes to their black hole router. Global Crossing uses an eBGP multi-hop
peer for these types of advertisements and others have their mechanisms as
well. On the flip side, through route-maps you could setup a community for
your customers to advertise to you traffic they wish to null, of course you
must take great care when doing this as to not allow something that could
really screw your network. In our network, all of our /32 nulls have a tag
applied from our black hole router, which gets propagated via OSPF then
eventually gets handed off to our peers using either a community or
multi-hop neighbor.

---
Jordan Medlen
Chief Technology Officer and Architect
Sago Networks 

-----Original Message-----
From: owner-nanog () merit edu [mailto:owner-nanog () merit edu] On Behalf Of
Payam Tarverdyan Chychi
Sent: Sunday, August 13, 2006 2:24 PM
To: Michael Nicks
Cc: nanog () nanog org
Subject: Re: [Full-disclosure] what can be done with botnet C&C's?


Though placing a /32 to a discarded interface helps the situation, you are
now fully disabling your client that uses the /32... I do agree that it
definitely helps the situation... specially when the attack is a few mil pps
or perhaps even few gigs/sec  in which case a customer /32  or bigger. being
down is about 100x better then your network being down.

so my question is then how do you use the same method for your peering
sessions (assuming you do peering on a private or public level)... seeing
how 95% of peers will not allow such specific entries such as /32 into their
tables... so in case of an attack you are left with either having to take
down the peering session or stop advertising the prefix though that peer.

Just curious as to how you go about it...

cheers,
-Payam




I hate to stir the flames again, but this idea sounds a lot like RBLs.  
:)

All kidding aside, I'm curious as to when we will reach the point 
where the devices of our networks will be able to share information 
regarding sporadic bursts or predefined traffic patterns in network 
traffic within a certain time frame, determine it is a related 
outgoing (or incoming) attack, and mitigate/stop the traffic. I think 
it certainly is possible to accomplish this on a per-router level, but 
being able to have the devices communicate and share information 
between one another is a completely separate thing. (New protocol 
perhaps.)

The only real method that I really have in my toolkit to stop incoming 
DDoS on a AS-wide perspective is originating a /32 within an AS with a 
next-hop of a discard interface.

Something similar to that nature but more flexible and designed for 
the sole purpose of preventing/stopping abuse would be a very nice
feature.

Cheers.
-Michael

--
Michael Nicks
Network Engineer
KanREN
e: mtnicks () kanren net
o: +1-785-856-9800 x221
m: +1-913-378-6516

Payam Tarverdyan Chychi wrote:
 I've been reading on this subject for the last several weeks and it 
seems as if everyone just like to come up with out of the box ideas 
that are not realistic for today's network environments

J.Oquendo, thanks for the Smurf example . as there are still
admins/engineers at large networks that have no clue as to what they 
are doing. so QoS is for sure out of the question.. at least at this 
time.

Depending on agents to take actions and protecting our networks is 
even a bigger joke. Back in late 90s where kiddies were using the 
simplest types of C&C, open wide irc networks with visible Channels 
and no encryptions. and agents couldn't do anything unless the attack 
was big enough to take down Amazon, yahoo, Microsoft or some other 
major provider with enough $$$ to start an investigation.

So what makes you think that agents are of any help in today's world 
where c&c have gotten so much more sophisticated, use backup private 
servers, encryption, tunneling and much much more..

In my opinion, the only way to really start cracking down on c&c and 
put an end to it is the cooperation of major ISP's. I realize that 
most isp's cant/wont setup a security team to just investigate c&c / 
attacks (would this really fall under the Abuse team?) but perhaps If 
all major networks worked together and created a active db list of 
c&c found either on their networks or attacking ones network. then it 
would be much much easier to trace back c&c and dispose of them.

Unfortunately, we don't live in a perfect world and most isp's hate 
sharing any information. I guess its better for them to have a bigger 
ego than a safer / more stable network.

Please feel free to correct me if I am wrong.

-Payam



--
--
Payam Tarverdyan Chychi
Network Analyst



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