Disable PING

[addvalue]

Any idea how to do it?

[no1v2]

Block people from pinging your server, or block users on your server from using ping? Either way, use your OS's packet filter to drop them and traceroute requests/responses. If it's the latter also remove their access to the ping and traceroute commands.


In Linux 2.4.x (using iptables) if you want to block others from pinging your server:

iptables -I INPUT -i lo -j ACCEPT
iptables -A INPUT -p icmp --icmp-type echo-request
iptables -A INPUT -p udp --dport traceroute:33498 -j DROP

Then save it:

iptables-save > /etc/iptables (or whatever filename you want to use)

Then add:

iptables-restore < /etc/iptables

to rc.local to reload it on boot. If you also want to save the counters use -c with both iptables-save and iptables-restore, and add a cronjob that periodically saves the counters, in case your server crashes.


If you want to block your users from pinging other servers in Linux 2.4.x with iptables, do:

iptables -I OUTPUT -o lo -j ACCEPT
iptables -A OUTPUT -p icmp --icmp-type echo-request -j DROP
iptables -A OUTPUT -p udp --dport traceroute:33498 -j DROP

Also adjust the permissions on ping and traceroute for a little added security (they can always upload their own).


If you don't know how TCP/IP, iptables, ping, and traceroute work, don't do any of this until you do! Make sure you understand exactly what this is doing. You also might need to adjust the rules I suggested if you have others.