Comments on: Disable ICMP echo (ping) responses in Linux

By: Guest

Guest — Fri, 17 Dec 2004 01:55:21 +0000

thanks for the tip! complete newbie to Linux but managed to get 100% stealth enabled in the firewall….
using your tips page.. only had to disable ping to achieve it! thanx again! :P

By: Anonymous

Anonymous — Fri, 24 Sep 2004 19:23:15 +0000

Just have your monitoring service try to connect to an open port (FTP, POP3, SMTP, WEB, SSH, Etc.) instead of going through the trouble of installed firewall software and configuring it. I use hyperspin.com and they can try to connect to a specific port instead or in addition to a classic ping.

By: Anonymous

Anonymous — Wed, 04 Aug 2004 23:01:21 +0000

But that would stop pings altogether. If you have a monitoring service, this would hurt you. You would never know if your server went down.

I would suggest installing APF fire wall, then do this:
pico -w /etc/apf/conf.apf

Change this:
IG_ICMP_TYPES=”3,5,11,0,30,8″

To this:
IG_ICMP_TYPES=”3,5,11,0,30″

So, if you have a monitoring service, add the monitor’s IP to the alallow_hosts.rules file.

THEN:
service apf restart

That would block pings from all outside sources except the IP’s you explicitly allow.