IPtable Server hanging

IPtable Server hanging

[hare ram]

Hi all


iam running iptable 1.2.8 on RH - pIII dual CPU 550mhz, 512MB RAM
i have connected to internet eth0
eth1 and eth2 connected to my clients

after i connected the Links to eth1 and eth2
the CPU load goes to 100% both

when i drop the ICMP in INPUT and FORWARD
the CPU load go to 5%

what could the problem, how can i resolve this problem
what is the problem is this ICMP flood or Syn attack or DoS attack

can any one suggest good tools and script to over come this problem

hare

Re: IPtable Server hanging

[Chris Brenton]

On Thu, 2003-12-04 at 08:00, hare ram wrote:
>
> after i connected the Links to eth1 and eth2
> the CPU load goes to 100% both
> 
> when i drop the ICMP in INPUT and FORWARD
> the CPU load go to 5%
> 
> what could the problem,

Too much ICMP traffic? ;-)

>  how can i resolve this problem
> what is the problem is this ICMP flood or Syn attack or DoS attack

Sounds like an ICMP flood, possibly due to Nachi or some variant.

Start logging traffic. That will tell you which IP is originating the
flood. If its internal systems, cleaning and patching is in order.

HTH,
C