前言：
在CentOS8中，我们常用的network.service服务就被NetworkManager.service服务代替了，同样的，IP的配置方法也发生了改变，那么如果想使用network.service服务去管理/配置系统网络怎么办呢？下面带你梦回network.service
NetworkManager.service
systemctl stop NetworkManager
systemctl disable NetworkManager
执行结果：
[root@localhost ~]# systemctl stop NetworkManager
[root@localhost ~]# systemctl disable NetworkManager
Removed /etc/systemd/system/multi-user.target.wants/NetworkManager.service.
Removed /etc/systemd/system/dbus-org.freedesktop.nm-dispatcher.service.
Removed /etc/systemd/system/network-online.target.wants/NetworkManager-wait-online.service.
到这里，NetworkManager服务就停止工作了，这时候可以先安装network-scripts（也就是network.service)了
network-scripts
静默安装(-q)
dnf install -y -q network-scripts
安装过程:
[root@localhost ~]# dnf install -y -q network-scripts
警告：/var/cache/dnf/BaseOS-929b586ef1f72f69/packages/network-scripts-10.00.6-1.el8_2.1.x86_64.rpm: 头V3 RSA/SHA256 Signature, 密钥 ID 8483c65d: NOKEY
导入 GPG 公钥 0x8483C65D:
Userid: "CentOS (CentOS Official Signing Key) <security@centos.org>"
指纹: 99DB 70FA E1D7 CE22 7FB6 4882 05B5 55B3 8483 C65D
来自: /etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
[root@localhost ~]#
此时，服务安装完成了，接下来开始启用该服务
启用之前再次确保NetworkManager关闭
systemctl stop NetworkManager
systemctl start network
systemctl enable network
systemctl status network
执行结果：
[root@localhost ~]# systemctl stop NetworkManager
[root@localhost ~]# systemctl start network
[root@localhost ~]# systemctl enable network
network.service is not a native service, redirecting to systemd-sysv-install.
Executing: /usr/lib/systemd/systemd-sysv-install enable network
[root@localhost ~]# systemctl status network
● network.service - LSB: Bring up/down networking
Loaded: loaded (/etc/rc.d/init.d/network; generated)
Active: active (running) since Fri 2020-07-03 12:49:02 EDT; 1min 46s ago
Docs: man:systemd-sysv-generator(8)
Tasks: 2 (limit: 11302)
Memory: 10.2M
CGroup: /system.slice/network.service
├─23350 /sbin/dhclient -1 -q -lf /var/lib/dhclient/dhclient-37ed0dcd-4d32-4c1e-aaa1-6371494d4541-ens33.lease -pf /run/dhclient-ens33.pid ens33
└─23463 /sbin/dhclient -1 -q -lf /var/lib/dhclient/dhclient-c87fa705-ed9f-4e03-b25a-142389898ff0-ens34.lease -pf /run/dhclient-ens34.pid ens34
7月 03 12:48:58 localhost network[23169]: 正在打开接口 ens34：
7月 03 12:48:58 localhost dhclient[23438]: Created duid "\000\004\305\214\015\204\360\376Az\212\354\216<g\262\342\374".
7月 03 12:48:58 localhost dhclient[23438]: DHCPDISCOVER on ens34 to 255.255.255.255 port 67 interval 6 (xid=0x986dfb66)
7月 03 12:48:59 localhost dhclient[23438]: DHCPREQUEST on ens34 to 255.255.255.255 port 67 (xid=0x986dfb66)
7月 03 12:48:59 localhost dhclient[23438]: DHCPOFFER from 10.1.1.254
7月 03 12:48:59 localhost dhclient[23438]: DHCPACK from 10.1.1.254 (xid=0x986dfb66)
7月 03 12:49:01 localhost dhclient[23438]: bound to 10.1.1.134 -- renewal in 847 seconds.
7月 03 12:49:01 localhost network[23169]: 正在确定 ens34 的 IP 信息... 完成。
7月 03 12:49:02 localhost network[23169]: [ 确定 ]
7月 03 12:49:02 localhost systemd[1]: Started LSB: Bring up/down networking.
此时，network服务已经启动成功了，那么下面就可以对NetworkManager进行卸载了。
NetworkManager（可选）执行卸载命令：
dnf remove -y NetworkManager
执行结果：
[root@localhost ~]# dnf remove -y NetworkManager
依赖关系解决。
==================================================================================================================================================================================================================================================
软件包 架构 版本 仓库 大小
==================================================================================================================================================================================================================================================
移除:
NetworkManager x86_64 1:1.22.8-4.el8 @anaconda 8.6 M
移除依赖的软件包:
NetworkManager-tui x86_64 1:1.22.8-4.el8 @anaconda 895 k
cockpit x86_64 211.3-1.el8 @anaconda 53 k
清除未被使用的依赖关系:
NetworkManager-libnm x86_64 1:1.22.8-4.el8 @anaconda 9.5 M
NetworkManager-team x86_64 1:1.22.8-4.el8 @anaconda 52 k
centos-logos x86_64 80.5-2.el8 @anaconda 699 k
cockpit-bridge x86_64 211.3-1.el8 @anaconda 1.0 M
cockpit-system noarch 211.3-1.el8 @anaconda 2.3 M
cockpit-ws x86_64 211.3-1.el8 @anaconda 2.2 M
glib-networking x86_64 2.56.1-1.1.el8 @anaconda 519 k
gsettings-desktop-schemas x86_64 3.32.0-4.el8 @anaconda 4.0 M
json-glib x86_64 1.4.4-1.el8 @anaconda 518 k
libdaemon x86_64 0.14-15.el8 @anaconda 63 k
libmodman x86_64 2.0.1-17.el8 @anaconda 68 k
libndp x86_64 1.7-3.el8 @anaconda 79 k
libnl3-cli x86_64 3.5.0-1.el8 @anaconda 819 k
libproxy x86_64 0.4.15-5.2.el8 @anaconda 197 k
libteam x86_64 1.29-1.el8 @anaconda 103 k
network-scripts-team x86_64 1.29-1.el8 @BaseOS 6.6 k
newt x86_64 0.52.20-11.el8 @anaconda 212 k
slang x86_64 2.3.2-3.el8 @anaconda 1.3 M
teamd x86_64 1.29-1.el8 @anaconda 271 k
事务概要
==================================================================================================================================================================================================================================================
移除 22 软件包
将会释放空间：33 M
运行事务检查
事务检查成功。
运行事务测试
事务测试成功。
运行事务
准备中 : 1/1
运行脚本: NetworkManager-tui-1:1.22.8-4.el8.x86_64 1/1
删除 : NetworkManager-tui-1:1.22.8-4.el8.x86_64 1/22
删除 : cockpit-211.3-1.el8.x86_64 2/22
删除 : cockpit-system-211.3-1.el8.noarch 3/22
运行脚本: cockpit-ws-211.3-1.el8.x86_64 4/22
删除 : cockpit-ws-211.3-1.el8.x86_64 4/22
运行脚本: cockpit-ws-211.3-1.el8.x86_64 4/22
删除 : cockpit-bridge-211.3-1.el8.x86_64 5/22
删除 : glib-networking-2.56.1-1.1.el8.x86_64 6/22
删除 : NetworkManager-team-1:1.22.8-4.el8.x86_64 7/22
运行脚本: NetworkManager-1:1.22.8-4.el8.x86_64 8/22
删除 : NetworkManager-1:1.22.8-4.el8.x86_64 8/22
运行脚本: NetworkManager-1:1.22.8-4.el8.x86_64 8/22
删除 : teamd-1.29-1.el8.x86_64 9/22
运行脚本: teamd-1.29-1.el8.x86_64 9/22
删除 : libteam-1.29-1.el8.x86_64 10/22
运行脚本: libteam-1.29-1.el8.x86_64 10/22
删除 : newt-0.52.20-11.el8.x86_64 11/22
删除 : network-scripts-team-1.29-1.el8.x86_64 12/22
删除 : gsettings-desktop-schemas-3.32.0-4.el8.x86_64 13/22
删除 : centos-logos-80.5-2.el8.x86_64 14/22
运行脚本: centos-logos-80.5-2.el8.x86_64 14/22
删除 : libproxy-0.4.15-5.2.el8.x86_64 15/22
运行脚本: libproxy-0.4.15-5.2.el8.x86_64 15/22
删除 : libmodman-2.0.1-17.el8.x86_64 16/22
运行脚本: libmodman-2.0.1-17.el8.x86_64 16/22
删除 : slang-2.3.2-3.el8.x86_64 17/22
删除 : libnl3-cli-3.5.0-1.el8.x86_64 18/22
运行脚本: libnl3-cli-3.5.0-1.el8.x86_64 18/22
删除 : libdaemon-0.14-15.el8.x86_64 19/22
删除 : NetworkManager-libnm-1:1.22.8-4.el8.x86_64 20/22
运行脚本: NetworkManager-libnm-1:1.22.8-4.el8.x86_64 20/22
删除 : libndp-1.7-3.el8.x86_64 21/22
运行脚本: libndp-1.7-3.el8.x86_64 21/22
删除 : json-glib-1.4.4-1.el8.x86_64 22/22
运行脚本: json-glib-1.4.4-1.el8.x86_64 22/22
验证 : NetworkManager-1:1.22.8-4.el8.x86_64 1/22
验证 : NetworkManager-libnm-1:1.22.8-4.el8.x86_64 2/22
验证 : NetworkManager-team-1:1.22.8-4.el8.x86_64 3/22
验证 : NetworkManager-tui-1:1.22.8-4.el8.x86_64 4/22
验证 : centos-logos-80.5-2.el8.x86_64 5/22
验证 : cockpit-211.3-1.el8.x86_64 6/22
验证 : cockpit-bridge-211.3-1.el8.x86_64 7/22
验证 : cockpit-system-211.3-1.el8.noarch 8/22
验证 : cockpit-ws-211.3-1.el8.x86_64 9/22
验证 : glib-networking-2.56.1-1.1.el8.x86_64 10/22
验证 : gsettings-desktop-schemas-3.32.0-4.el8.x86_64 11/22
验证 : json-glib-1.4.4-1.el8.x86_64 12/22
验证 : libdaemon-0.14-15.el8.x86_64 13/22
验证 : libmodman-2.0.1-17.el8.x86_64 14/22
验证 : libndp-1.7-3.el8.x86_64 15/22
验证 : libnl3-cli-3.5.0-1.el8.x86_64 16/22
验证 : libproxy-0.4.15-5.2.el8.x86_64 17/22
验证 : libteam-1.29-1.el8.x86_64 18/22
验证 : network-scripts-team-1.29-1.el8.x86_64 19/22
验证 : newt-0.52.20-11.el8.x86_64 20/22
验证 : slang-2.3.2-3.el8.x86_64 21/22
验证 : teamd-1.29-1.el8.x86_64 22/22
已移除:
NetworkManager-1:1.22.8-4.el8.x86_64 NetworkManager-libnm-1:1.22.8-4.el8.x86_64 NetworkManager-team-1:1.22.8-4.el8.x86_64 NetworkManager-tui-1:1.22.8-4.el8.x86_64 centos-logos-80.5-2.el8.x86_64 cockpit-211.3-1.el8.x86_64
cockpit-bridge-211.3-1.el8.x86_64 cockpit-system-211.3-1.el8.noarch cockpit-ws-211.3-1.el8.x86_64 glib-networking-2.56.1-1.1.el8.x86_64 gsettings-desktop-schemas-3.32.0-4.el8.x86_64 json-glib-1.4.4-1.el8.x86_64
libdaemon-0.14-15.el8.x86_64 libmodman-2.0.1-17.el8.x86_64 libndp-1.7-3.el8.x86_64 libnl3-cli-3.5.0-1.el8.x86_64 libproxy-0.4.15-5.2.el8.x86_64 libteam-1.29-1.el8.x86_64
network-scripts-team-1.29-1.el8.x86_64 newt-0.52.20-11.el8.x86_64 slang-2.3.2-3.el8.x86_64 teamd-1.29-1.el8.x86_64
完毕！
[root@localhost ~]#
那么到这里，NetworkManager服务就没了，然后我们使用network服务进行管理网络
network服务管理网络首先进入我们熟悉的路径：
cd /etc/sysconfig/network-scripts/
ls
执行结果如下：
[root@localhost ~]# cd /etc/sysconfig/network-scripts/
[root@localhost network-scripts]# ls
ifcfg-ens33 ifdown ifdown-ippp ifdown-post ifdown-tunnel ifup-bnep ifup-ipv6 ifup-plusb ifup-sit init.ipv6-global
ifcfg-ens34 ifdown-bnep ifdown-ipv6 ifdown-routes ifup ifup-eth ifup-isdn ifup-post ifup-tunnel network-functions
ifcfg-lo ifdown-eth ifdown-isdn ifdown-sit ifup-aliases ifup-ippp ifup-plip ifup-routes ifup-wireless network-functions-ipv6
然后尝试更改IP地址:
此时，已经可以使用network服务进行管理IP了