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Block or Unblock Ping Request on Debian 10 - How to perform this task ?

This article covers how you can block/unblock ping requests to your Debian system. You will learn different ways for blocking/unblocking ping requests either temporarily or permanently.


The --query-icmp-block=<type> option can be used to determine if a type is confgured to allow or deny. 

The --add-icmp-block=<type> option can be used to block a certain type. 

The --remove-icmp-block=<type> option can be used to not block a certain type. 

After adding or removing a block, reload the firewall.


To block ping requests in Linux:

1. Edit /etc/sysctl.conf. Add the following line to your /etc/sysctl.conf : net.ipv4.icmp_echo_ignore_all=1. Then: sysctl -p.

2. Using iptables: iptables -I INPUT -p icmp --icmp-type echo-request -j DROP.

3. With cron. Run crontab -e as root, then add the following line: @reboot echo "1" > /proc/sys/net/ipv4/icmp_echo_ignore_all.


To block ping in iptables:

1. Add a rule that tells the iptables firewall to block ping in and out of a server by controlling the ICMP requests.

2. Remove the rule that tells the iptables firewall to allow ping in and out of a server by controlling the ICMP requests.


To enable ping on Linux server?

# iptables -D INPUT -p icmp --icmp-type echo-request -j REJECT D : 

This command switch is used to delete the rule. Once the ping enabled, the server should now respond to ping requests


How to block or unblock ping requests on Ubuntu Server 20.04 LTS ?

This article will guide you on steps to block or unblock #ping requests on #Ubuntu Server 20.04 LTS. Also you will learn how to unblock the ping requests in case you need to use ping for system administration and troubleshooting.

To block #ping requests in #Linux:

You can implement blocking ICMP messages in your Linux system by adding the below #kernel variable that will drop all ping packets. In order to make the above rule permanent, append following line to /etc/sysctl. conf file and, subsequently, apply the rule with sysctl command.