Linux's love-hate relationship with ping packages

Linux systems allow ping by default, but in some cases for security reasons, we set the server to disable ping. To temporarily allow the ping command, use the command:

echo 0 >/proc/sys/net/ipv4/icmp_ignore_all　　:0，代表允许；1，代表禁止

View current settings:

is 0, for this we can try pinging

Use the ping command

Use -t to ping continuously

Permanently allow or disable ping, modify the configuration file /etc/sysctl.conf

Add a line as shown above, net.ipv4.icmp_echo_ignore_all=1

1 means prohibited, 0 means allowed. Save and exit after modification is completed

Execute sysctl -p to make the new configuration take effect

Test the ping again

As shown in the figure, after the configuration takes effect, the ping command cannot ping the same IP again. If you want to permanently allow the ping command, you only need to change the configuration file 1 to 0.

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