Information
nftables is a subsystem of the Linux kernel providing filtering and classification of network packets/datagrams/frames and is the successor to iptables.
Notes:
Support for using nftables as the back-end for firewalld was added in release v0.6.0. In Fedora 19 Linux derivatives, firewalld utilizes iptables as it's back-end by default.
firewalld may be configured as the front-end to nftables. If this case, nftables should be stopped and masked instead of removed.
Rationale:
Running both firewalld and nftables may lead to conflict.
Solution
Run the following command to remove nftables:
# zypper remove nftables
OR
Run the following command to stop and mask nftables:
systemctl --now mask nftables