[CentOS] firewalld / iptables / nftables

On Tue, Jun 09, 2020 at 02:19:17PM +0200, Leon Fauster via CentOS wrote:
>
> Despite that the migration of our applications comes with a significant
> workload. It seems that also every aspect of common services had changed
> with EL8.
> 
> In EL8 firewalld uses nftables as backend. I wonder why iptables does not
> list any rules while also configured to use nftables as backend.
> 
> # iptables -V
> iptables v1.8.2 (nf_tables)
> 
> 
> # firewall-cmd --list-all |egrep -o '22|ssh'
> ssh
> 
> # nft list ruleset | egrep -o '22|ssh'
> ssh
> 
> # iptables -L -n | egrep -o '22|ssh'
> <EMPTY>
> 
> Any hints?

'iptables' and 'nftables' are competing technologies.  In CentOS 8,
firewalld's backend was switched from iptables to nftables.  So it
would be expected that the iptables command wouldn't have any rules
defined, it isn't being used by firewalld.

-- 
Jonathan Billings <billings at negate.org>