Re: DoS "Probing" on one of our hosts

[Edward Balas <ebalas () iu edu>]

On Sun, 29 Jun 2003, Christopher Kunz wrote:

> Hey,
>
> we have been encountering three short DoS attacks during the weekend - 
> each one around 1 hour in length and with about 100mbit worth of 
> bandwidth. So far, we've yet to determine even the most basic stuff, 
> since we don't seem to have any logging. I have two questions regarding 
> this:

> 1. isn't one hour a pretty short time for a DoS? I've seen attacks on 
> other nets lasting for hours, sometimes up to a day...  

Depends on the nature of the attack, from what I have seen this is not
uncommen.  Ive seen this type agaist IRC servers quite often.


> 2. is there any tool to determine the source IPs of the attack (even if 
> they're spoofed, I'd like to see _anything_)? Snort sits on the attacked 
> host and happily reports SQL/Slammer and other trivial stuff, but goes 
> through one of the attacks without picking any signatures up.

If you have access to the netflow accounting data for the routers, then
you can backtrace the traffic to the incomming network.  Or if you dont, 
your ISP may.  They probably wont be interesting in helping backtrack 
this given the short duration.

Edward Balas
 
> Regards,
>
> --ck


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