第一步：保存iptables规则到文件 /etc/iptables.rules
iptables-save > /etc/iptables.rules第二步：将如下代码写入 /etc/rc.local
#!/bin/sh
iptables-restore < /etc/iptables.rules第三步：为 /etc/rc.local 文件赋可执行权限
chmod +x /etc/rc.local第四步：编辑文件 /lib/systemd/system/rc.local.service 内容如下：
# SPDX-License-Identifier: LGPL-2.1+
#
# This file is part of systemd.
#
# systemd is free software; you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 of the License, or
# (at your option) any later version.# This unit gets pulled automatically into multi-user.target by
# systemd-rc-local-generator if /etc/rc.local is executable.
[Unit]
Description=/etc/rc.local Compatibility
Documentation=man:systemd-rc-local-generator(8)
ConditionFileIsExecutable=/etc/rc.local
After=network.target[Service]
Type=forking
ExecStart=/etc/rc.local start
TimeoutSec=0
RemainAfterExit=yes
GuessMainPID=no
第五步：设置 rc.local 为开机启动
systemctl enable rc.local第六步：重启系统后 查看 iptables 规则是否还在
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