Re: [CentOS] IPtables block user from outbound ICMP

Am 24.02.2016 um 15:42 schrieb John Cenile:

Hello,

Is it possible at all to block all users other than root from sending outbound ICMP packets on an interface?

At the moment we have the following two rules in our IPtables config:

iptables -A OUTPUT -o eth1 -m owner --uid-owner 0 -j ACCEPT iptables -A OUTPUT -o eth1 -j DROP

But this still allows ICMP for some reason (but *does* block other TCP/UDP packets, which is what we want, as well as ICMP).

Thanks.

What do you want to achieve by not allowing outbound ICMP traffic?

Are you aware that ICMP has a larger set of different types, several of them required for a functional network.

Alexander