Re: DoS by small packets: eth0: Too much work at interrupt, IntrStatus=0x0001.

[Milan Keršláger <milan kerslager pslib cz>]

On Thu, Jul 08, 2004 at 09:40:08AM -0600, Stephen Smoogen wrote:
> On Thu, 2004-07-08 at 04:51, Milan Keršláger wrote:
> > Hi,
> > 
> > I have a trouble with DoS attacks to one internal machine through RHEL3
> > router. It seems that a lot of small packets causing DoS (100Mbps links)
> > on my router even I shut down my firewall rules.
> 
> Ok need more info as I am confused.
> 
> 1) What is the router? Is it the RHEL box? {CPU, MB, PCI speed, etc}
> 2) What is the DOS? Is it the machine on the network hitting the router
> or things on the internet trying to get to the networked machine
> 3) Is the UTP 10baseT or 100baseT

As I told - this is 2x100 Mbps full duplex, Athlon 1.1 GHz, 256MB RAM
(standard 33MHz PCI bus). I tryed latest 3C905CX-TXM cards and one Intel
E100 too with the same effect, ie just after plugging UTP cable to the
machine it slows down and freeze until UTP cable is unplugged. The
machine is a router and the traffic has been sent to the machine behind
this router.

This router is connected to the multi Gbps backbone Cisco router so I'm
able to receive and send 100 Mbps data stream.

-- 
                        Milan Kerslager
                        E-mail: milan kerslager pslib cz
                        WWW:    http://www.pslib.cz/~kerslage/