Re: DoS "Probing" on one of our hosts

[Christopher Kunz <chrislist () de-punkt de>]

Chris Calvert wrote:
> DoS attack duration can vary considerably.  I've seen attacks that last
> over a day or two, it really depends on how persistent the attacker is
> and how robust the target is.  100 Mbit attacks might bring down a small
> hosting service, or get shrugged off by a target on a larger pipe.

Right. Although our service provider seems to have a quite robust
connection, the bottle neck is of course our rack's uplink.

> Get a capture of the traffic and do some analysis.  
> help analyzing the traffic. For example, you might be getting hit with
> huge packets which saturate your Internet connection and/or inbound
> interface, or you may be getting hit with small packets but at a
> packet/second rate that your switch, modem, interface, or whatever
> cannot handle.  There may be no signatures to detect, you might simply
> be the target of a brute force traffic DoS.

I suspect (after ruling out having a warez distro site on the box) the
latter. Our uplink provider monitors traffic for us and the spikes are
there - it's not that our uplink switch just stops working (as it would
if too many packets per second came in), the traffic really is there. So
my wild guess was that we were just ping -f'ed, stacheldrahted or
something like that.

--ck

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