Q. How do I disable or drop all ping packats all together?
A. Generally you can use iptables to block or allow ping requests.
You can setup kernel variable to drop all ping packets. Type the following command at shell prompt:
# echo “1” > /proc/sys/net/ipv4/icmp_echo_ignore_all
This instructs the kernel to simply ignore all ping requests (ICMP type 0 messages). To enable ping request type the command:
echo “0” > /proc/sys/net/ipv4/icmp_echo_ignore_all
You can add following line to /etc/sysctl.conf file:
# vi /etc/sysctl.conf
Append following line:
net.ipv4.icmp_echo_ignore_all = 1
Save and close the file.
Sometimes ping request can be handy for testing your own server. You can disable ICMP type 0 messages in the firewall so that local administrators to continue to use ping command for their own server. Following command block all ICMP packets including ping request:
# iptables -A INPUT -p icmp -j DROP
