On 12/07/16 18:20, Jeff White wrote:
> On CentOS 7 with firewalld I have a box with numerous
> interfaces acting as a NAT gateway. This works but I
> noticed that it routes/forwards traffic not just from my
> internal zone to external zone but also between interfaces
> within the internal zone. How can I prevent that traffic?
>
> I've tried adding direct and rich rules to deny the
> traffic but it doesn't work. Direct:
>
> firewall-cmd --direct --add-rule ipv4 filter INPUT 0 -s
> 10.110.4.0/22 -d 10.110.0.0/22 -j REJECT
>
> That command works, and I see it in `iptables -L` but
> traffic is still allowed. Rich:
>
> # firewall-cmd --zone=trusted --add-rich-rule='rule
> family=ipv4 source address=10.110.4.0/22 destination
> address=10.110.0.0/22 reject'
> Error: INVALID_RULE: destination action
>
> I can't find any explanation of what that error means.
> So, how do you tell firewalld to stop forwarding traffic
> between interfaces?
>
>
>
> # firewall-cmd --get-active-zones
> public
> interfaces: ens161 ens193
> trusted
> interfaces: ens192 ens224 ens256 lo
>
> # firewall-cmd --list-all
> public (default, active)
> interfaces: ens161 ens193
> sources:
> services: dhcpv6-client ssh
> ports:
> masquerade: yes
> forward-ports:
> icmp-blocks:
> rich rules:
>
yes, to me too it sort of defines basic logic - one would
expect to be able with a "rich rule" to block/ban a host
(actually there are quite few articles on the net stating it
should be doing that)
public (active)
interfaces: em3
sources:
services: dhcpv6-client ssh
ports:
masquerade: yes
forward-ports:
icmp-blocks:
rich rules:
rule family="ipv4" source address="192.168.2.0/24"
reject
yet host from 192.168.2.0/24 (which is firewalld's zone
work) are able to masquerade and access all (in this case
whole Internet) behind em3 interface.
It smells like a bug to me.