[root@localhost~]# systemctl enable iptables
Created symlink from /etc/systemd/system/basic.target.wants/iptables.service to /usr/lib/systemd/system/iptables.service.
[root@localhost~]# systemctl start iptables
Job for iptables.service failed because the control process exited with error code. See "systemctl status iptables.service" and "journalctl -xe" for details.
[root@localhost~]# systemctl status iptables.service
● iptables.service - IPv4 firewall with iptablesLoaded: loaded (/usr/lib/systemd/system/iptables.service; enabled; vendor preset: disabled)Active: failed (Result: exit-code) since 一 2020-08-31 16:45:01 CST; 2min 53s agoProcess: 16808 ExecStart=/usr/libexec/iptables/iptables.init start (code=exited, status=1/FAILURE)Main PID: 16808 (code=exited, status=1/FAILURE)8月 31 16:45:01 localhost.localdomain systemd[1]: Starting IPv4 firewall with iptables...
8月 31 16:45:01 localhost.localdomain iptables.init[16808]: iptables: Applying firewall rules: iptables-restore: line 1 failed
8月 31 16:45:01 localhost.localdomain iptables.init[16808]: [失败]
8月 31 16:45:01 localhost.localdomain systemd[1]: iptables.service: main process exited, code=exited, status=1/FAILURE
8月 31 16:45:01 localhost.localdomain systemd[1]: Failed to start IPv4 firewall with iptables.
8月 31 16:45:01 localhost.localdomain systemd[1]: Unit iptables.service entered failed state.
8月 31 16:45:01 localhost.localdomain systemd[1]: iptables.service failed.

[root@localhost~]# systemctl start firewalld
Job for firewalld.service failed because the control process exited with error code. See "systemctl status firewalld.service" and "journalctl -xe" for details.
[root@localhost~]# vim /usr/sbin/firewalld
##将 #!/usr/bin/python -Es修改为#!/usr/bin/python2 -Es或#!/usr/bin/python2.7 -Es
[root@localhost~]# service firewalld start
Redirecting to /bin/systemctl start  firewalld.service
[root@localhost~]# systemctl start firewalld

[root@localhost~]# systemctl status firewalld -l;firewall-cmd --state
● firewalld.service - firewalld - dynamic firewall daemonLoaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled; vendor preset: enabled)Active: inactive (dead) since 一 2020-08-31 17:06:44 CST; 4min 25s agoDocs: man:firewalld(1)Process: 17225 ExecStart=/usr/sbin/firewalld --nofork --nopid $FIREWALLD_ARGS (code=exited, status=0/SUCCESS)Main PID: 17225 (code=exited, status=0/SUCCESS)8月 31 17:06:44 localhost.localdomain firewalld[17225]: WARNING: AllowZoneDrifting is enabled. This is considered an insecure configuration option. It will be removed in a future release. Please consider disabling it now.
8月 31 17:06:44 localhost.localdomain firewalld[17225]: WARNING: ipset not usable, disabling ipset usage in firewall.
8月 31 17:06:44 localhost.localdomain firewalld[17225]: WARNING: Failed to load nf_conntrack module: modprobe: ERROR: could not insert 'nf_conntrack': Unknown symbol in module, or unknown parameter (see dmesg)modprobe: ERROR: Error running install command for nf_conntrackmodprobe: ERROR: could not insert 'nf_conntrack': Operation not permitted
8月 31 17:06:44 localhost.localdomain firewalld[17225]: ERROR: Failed to read file "/proc/sys/net/netfilter/nf_conntrack_helper": [Errno 2] 没有那个文件或目录: '/proc/sys/net/netfilter/nf_conntrack_helper'
8月 31 17:06:44 localhost.localdomain firewalld[17225]: WARNING: Failed to get and parse nf_conntrack_helper setting
8月 31 17:06:44 localhost.localdomain firewalld[17225]: WARNING: iptables not usable, disabling IPv4 firewall.
8月 31 17:06:44 localhost.localdomain firewalld[17225]: WARNING: ip6tables not usable, disabling IPv6 firewall.
8月 31 17:06:44 localhost.localdomain firewalld[17225]: WARNING: ebtables not usable, disabling ethernet bridge firewall.
8月 31 17:06:44 localhost.localdomain firewalld[17225]: FATAL ERROR: No IPv4 and IPv6 firewall.
8月 31 17:06:44 localhost.localdomain firewalld[17225]: ERROR: Raising SystemExit in run_server
not running

grant all privileges on *.* to 'root'@'192.168.101.151' identified by 'tt111222';
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'identified by 'tt111222'' at line 1

mysql> grant all privileges on *.* to 'root'@'192.168.101.151' IDENTIFIED WITH mysql_native_password BY 'tt111222';
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'IDENTIFIED WITH mysql_native_password BY 'tt111222'' at line 1

mysql> grant all privileges on *.* to 'root'@'192.168.101.151' IDENTIFIED WITH 'tt111222';
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'IDENTIFIED WITH 'tt111222'' at line 1mysql> grant all privileges on *.* to 'root'@'%' with grant option;
mysql> grant all privileges on *.* to 'root'@'localhost' with grant option;
Query OK, 0 rows affected (0.22 sec)mysql> grant all privileges on *.* to 'root'@'192.168.101.151' with grant option;
ERROR 1410 (42000): You are not allowed to create a user with GRANT

mysql> use mysql;create user edmond identified by 'tt111222';
Database changed
Query OK, 0 rows affected (0.03 sec)
mysql> GRANT EXECUTE,INSERT,SELECT,UPDATE,DELETE ON *.* TO 'edmond'@'%';
Query OK, 0 rows affected (0.00 sec)mysql> FLUSH   PRIVILEGES;
Query OK, 0 rows affected (0.01 sec)