# systemctl enable firewalld.service
# systemctl start firewalld
# systemctl status firewalld
* firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled; vendor preset: enabled)
   Active: active (running) since Tue 2019-08-20 17:54:23 EDT; 5s ago
     Docs: man:firewalld(1)
 Main PID: 756 (firewalld)
   CGroup: /system.slice/firewalld.service
           |-756 /usr/bin/python -Es /usr/sbin/firewalld --nofork --nopid
           `-800 /usr/bin/python -Es /usr/sbin/firewalld --nofork --nopid

Aug 20 17:54:22 server systemd[1]: Starting firewalld - dynamic firewall daemon...
Aug 20 17:54:23 server systemd[1]: Started firewalld - dynamic firewall daemon.
Aug 20 17:54:26 server firewalld[756]: WARNING: ipset not usable, disabling ipset usage in firewall.
Aug 20 17:54:27 server firewalld[756]: ERROR: Failed to read file "/proc/sys/net/netfilter/nf_conntrack_helper": [Errno 2] No such file or directory: '/proc/sys/net/netfilter/nf_conntrack_helper'
Aug 20 17:54:27 server firewalld[756]: WARNING: Failed to get and parse nf_conntrack_helper setting
Aug 20 17:54:27 server firewalld[756]: WARNING: ebtables not usable, disabling ethernet bridge firewall.

# depmod
depmod: ERROR: could not open directory /lib/modules/2.6.32-042stab120.19: No such file or directory
depmod: FATAL: could not search modules: No such file or directory