Hey, I want to know how to block computers in a subnet, that they do not be able to ping other computers on the same subnet,
Thanks.

So you want a subnet that isolates PC communication from each other?

This can be done with higher-end switches. Home switches generally can't do that. The feature you're looking for is sometimes called "Private VLANs" which in essence prevents all communication within a VLAN between devices but allows access only to the gateway. Any broadcasts within a subnet are also prevented (except to the gateway).

Thanks for your Answer, Yep That's what I want.

Thanks cajalat for your answer, It really been very informative,, but I wanted to know can we do that with an OS distribution or IPSec Service?

You can definitely accomplish what you want with the OS. But you will need to make the changes on every PC in the subnet. Each OS has a different way of doing this but ultimately what you want to do is block any inbound ICMP-Echo Request. This will allow all other ICMP messages to work except for PINGs.

So each computer that has this block enabled will not respond to someone else trying to ping them. They will be able to ping other systems though (so long as the other system doesn't have this block on it).

So if you have:

Machine A: blocks inbound ICMP Echo Request
Machine B: blocks inbound ICMP Echo Request
Machine C: No changes

Then

Machine A can ping C but not B
Machine B can ping C but not A
Machine C can't ping A or B

Keep in mind that "ping" is just a tool to check if a destination machine is "alive". Blocking Ping alone will not prevent someone from figuring out if your machine is "alive". They can run a traceroute for example to see if it responds.

Thanks cajalat for your answer & time.