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Re: block pings

On Wed, 30 Aug 2000, Danny Pansters wrote:

> On Tue, 29 Aug 2000, Nick wrote:
> > how do you stop linux from replying to pings like
> >
> > microsoft does.  you can't ping www.microsoft.com or www.msn.com
> >
> > thankx nick
> OK, I got curious since it involves icmp, so it's not done in 
> /etc/inetd.conf, and I didn't know how to do it. 
> All I can say is RTFM, it's right there in the icpm man page that 
> I tried first.
> Just put this in /etc/sysctl.conf to turn ping replies off:
> net/ipv4/icmp_echo_ignore_all=1
> Then run
> # sysctl -p
> But after that you should really go back to /etc/sysctl.conf and get rid of 
> it again (hint: it involves running sysctrl again :-).

Another fine hack would be this:

 ipchains -A input -i ppp0 -p icmp --icmp-type 8 -j DENY
 ipchains -A output -i ppp0 -p icmp --icmp-type 0 -j REJECT

ICMP type 8 is echo-request. type 0 is echo-reply.
Replace ppp0 by whatever you use to connect to the internet.

 Just my $0.02


email: sebastian.ritter@web.de

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