To disable the ICMP ping from certain Linux host, lets say which has IP of 192.168.0.100 use below command,
Type below command on the console of linux PC on which you are trying to enable / disable the ping.
$ sudo iptables -A INPUT -p icmp --icmp-type any -j REJECT
$ sudo iptables -A OUTPUT -p icmp --icmp-type any -j REJECT
Now, if you try to ping to same machine, we will get something like below,
$ ping 192.168.0.100
PING 192.168.0.100 (192.168.0.100) 56(84) bytes of data.
ping: sendmsg: Operation not permitted
ping: sendmsg: Operation not permitted
Now to enable the ICMP ping from same host, use the below commands,
$ sudo iptables -A INPUT -p icmp --icmp-type any -j ACCEPT
$ sudo iptables -A INPUT -p icmp --icmp-type any -j ACCEPT