how can i stop ping reply?

Guru Mind · 02-03-2006, 03:47 PM

hi everybody , i have newbie question

how can i stop ping reply videlicet how can i stop reply if anybody ping my IP , or just got my IP but don't got reply?

and sorry for bad english .

pljvaldez · 02-03-2006, 03:51 PM

I believe you just need to install a firewall and configure it to drop all packets.

ppuru · 02-03-2006, 04:23 PM

As root

echo 1 > /proc/sys/net/ipv4/icmp_echo_ignore_all

This will block all icmp requests.

To make this a permanent settings, add the line below to /etc/sysctl.conf

net.ipv4.icmp_echo_ignore_all = 0

As pljvalez suggested, you can also set a firewall rule to disable icmp reply.

Guru Mind · 02-03-2006, 06:05 PM

pljvaldez thank you but i wanna stop ping without firewall

ppuru thanks it's worked , but i try to edit sysctl.conf and put what you say but it dosn't worked

anyway thank .

ppuru · 02-03-2006, 06:14 PM

gurumind, my apologies, set

net.ipv4_icmp_echo_ignore_all = 1

to stop pings. setting it to 0 allows pings.

Guru Mind · 02-03-2006, 06:33 PM

ok ppuru , but would i must restart service or something like that?

and really thanks ppuru .

ppuru · 02-03-2006, 06:37 PM

no need, the next time you reboot your system, the icmp_echo_ignore_all will be set.

gilead · 02-03-2006, 09:41 PM

You don't need to reboot to make the settings take effect. If you've added the line to /etc/sysctl.conf, as root type sysctl -p

Guru Mind · 02-04-2006, 06:35 AM

after i type sysctl -p

error: "net.ipv4_icmp_echo_ignore_all" is an unknown key

any suggeste?

win32sux · 02-04-2006, 06:41 AM

Quote:

Originally Posted by Guru Mind

after i type sysctl -p

error: "net.ipv4_icmp_echo_ignore_all" is an unknown key

any suggeste?

try changing the first underscore to a period... like this:

Code:

net.ipv4.icmp_echo_ignore_all

iNeo · 02-04-2006, 08:59 AM

This is slightly off topic.
I know there is a way in which you can configure some message to be displayed when someone tries to ping our machine. Does anyone know how that is done?

win32sux · 02-04-2006, 09:07 AM

Quote:

Originally Posted by iNeo

This is slightly off topic.
I know there is a way in which you can configure some message to be displayed when someone tries to ping our machine. Does anyone know how that is done?

well, if you filter the pings with regular iptables instead of sysctl.conf it's just a matter of adding a LOG target rule... so anytime someone pings you it will show-up in /var/log/syslog:

Code:

iptables -I INPUT -p ICMP --icmp-type 8 \
-m state --state NEW -j LOG

dutler · 02-04-2006, 01:34 PM

are you suing a gui? check out he iptable instface guarddog

ppuru · 02-04-2006, 05:21 PM

Quote:

Originally Posted by win32sux

try changing the first underscore to a period... like this:

Code:

net.ipv4.icmp_echo_ignore_all

Thanks win32sux, sorry for the typo Gurumind.

net.ipv4.icmp_echo_ignore_all is the correct key.

sysctl -a gives a list of all settable parameters. Play around at your own risk.

Guru Mind · 02-04-2006, 06:17 PM

Thanks win32sux and ppuru for help

it's working now