Re: Attacking on Source Port 0 (ZERO)

[Shahab Vahabzadeh <sh.vahabzadeh () gmail com>]

Hi there,
It was TCP and I think it was not a DDoS attack because the traffic was not
heavy.
But I see abnormal cpu usage (%99) in my BRAS's which are Cisco 7206 VXR.
I think it act like a warm or some attacks which cause high CPU load in
some IOS.
Thanks

On Sun, Oct 14, 2012 at 5:13 PM, Dobbins, Roland <rdobbins () arbor net> wrote:

> On Oct 14, 2012, at 4:48 PM, Shahab Vahabzadeh wrote:
>
> > Does any body know what kind of attack can be come to port 0?
>
> If it's protocol 0, instead of port 0, it's likely a packet-flooding DDoS
> attack.
>
> If it's port 0, you may be incorrectly blocking non-initial fragments.
>  Alternately, it could represent a fragmented DDoS attack, either
> non-initial fragments fired directly against something on your network or
> as the result of a DNS reflection/amplification attack against something on
> your network.
>
> The log fragment you posted doesn't provide enough detail to make an
> informed judgement.  Also, you should not place servers behind a stateful
> firewall, anyways.
>
> -----------------------------------------------------------------------
> Roland Dobbins <rdobbins () arbor net> // <http://www.arbornetworks.com>
>
>           Luck is the residue of opportunity and design.
>
>                        -- John Milton


-- 
Regards,
Shahab Vahabzadeh, Network Engineer and System Administrator

Cell Phone: +1 (415) 871 0742
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