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Re: Iptables generic broadcast filter



You are all right, I must have thought on this before
sending this question..
Thanks
alex
On Wed, 2002-11-13 at 16:12, Matthew Kirkwood wrote:
> On 13 Nov 2002, Alex Ongena wrote:
> 
> > I want to drop all broadcasts on INPUT in a generic way
> > without knowing in advance on which subnet/netmask my
> > appliance is.
> 
> > # iptables -A INPUT -d *.*.*.255 -j DROP
> > # iptables -A INPUT -d *.*.255.255 -j DROP
> > # iptables -A INPUT -d *.255.255.255 -j DROP
> >
> > where * is a wildcard matching any ip.
> 
> Yes.  Netmasks don't need to be contiguous or MSB-aligned:
> 
> # iptables -A INPUT -d 0.0.0.255/0.0.0.255 -j DROP
> 
> will drop anything with an all-ones LSO.
> 
> Matthew.
> 
> 
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