Ping is not allowed under Ubuntu (Linux) (Disable ICMP protocol access)

It is necessary to prohibit the use of PING commands in Linux systems by using specialized hacking programs to steal information that is transmitted over a network line and to use stolen information to attack a specified server or system. In Linux, if you want the ping to be unresponsive and to ignore the ICMP package, we can enter the following command on the Linux command line:

disabling ICMP protocol access

Cause Ping to not respond, ignore ICMP package, enter:

echo 1 >/proc/sys/net/ipv4/icmp_echo_igore_all;

To resume using the ping command, enter:

echo 0 >/proc/sys/net/ipv4/icmp_echo_igore_all command.

Can be placed in/etc/rc.d/rc.local

Limit root

/etc/securetty
Tty1
#tty2---6

/etc/secuetty/access.conf
-:root:all EXCEPT Console