September 07, 2012
iptables: method to simply block Ping requests...
Sometimes a system administrator would simply like to block out all incoming ping requests - issue the following command in order to adjust iptables for this functionality:
/sbin/iptables -I INPUT -j DROP -p icmp --icmp-type echo-request
(this reads drop all input of protocol type icmp, specifically echo-request).
Then to drop the rule, simply obtain the index number of the iptables rule:
/sbin/iptables -L INPUT --line-numbers
Chain INPUT (policy ACCEPT)
num target prot opt source destination
1 DROP icmp -- anywhere anywhere icmp echo-request
(the block ICMP request in number 1)
Drop the entry:
/sbin/iptables -D INPUT 1