Firewall (4)-iptables (2) add and modify rules -A -R

(1) Prohibit a host to ping:
First prepare two hosts:

At this point, first clear all iptables rules

and then add our rules: prohibit our 192.168.19.131 host from connecting to 192.168.19.129:

This is what we found unable to ping

We can see that a message has been received, num has become 1

ps: Modify the host name:


(2) Modify the rules.
At this point, we add another host: 192.168.19.134.

We will change the prohibition of 192.168.19.131 above to prohibit 192.168.19.134:

At this time, I use my 192.168.19.134 host to ping192 .168.19.129:

It is found that it cannot be pinged.
Then use 192.168.19.131 to ping: it is

found that it can be pinged.