RHEL7 -- NetworkManager

RHEL7中默认的网络服务是由NetworkManager提供，NetworkManager可以动态控制和配置网络。

网络工具和应用

应用或工具	描述
NetworkManager	默认的网络守护进程
nmtui	NetworkManager基于光标文本的简单的图形用户接口
nmcli	和NetworkManager交互的命令行接口
control-center	GNOME提供的图形化接口工具
nm-connection-editor	A GTK+ 3 application available for certain tasks not yet handled by control-center

NetworkManager 的安装

# yum install NetworkManager

NetworkManager tui的安装

# yum install NetworkManager-tui

设置NetworkManager开启自启动

# systemctl enable NetworkManager

查看NetworkManager进程状态

# systemctl status NetworkManager
NetworkManager.service - Network Manager
   Loaded: loaded (/usr/lib/systemd/system/NetworkManager.service; enabled)
   Active: active (running) since Tue -- :: CST; 8min ago
 Main PID:  (NetworkManager)
   CGroup: /system.slice/NetworkManager.service
           └─ /usr/sbin/NetworkManager --no-daemon

Jul  :: localhost.localdomain NetworkManager[]: <info> (enp0s3): device state change: ip-check -> secondaries (reason 'none') [  ]
Jul  :: localhost.localdomain NetworkManager[]: <info> (enp0s3): device state change: secondaries -> activated (reason 'none') [  ]
Jul  :: localhost.localdomain NetworkManager[]: <info> NetworkManager state is now CONNECTED_LOCAL
Jul  :: localhost.localdomain NetworkManager[]: <info> Policy set 'eth0' (enp0s3) as default for IPv4 routing and DNS.
Jul  :: localhost.localdomain NetworkManager[]: <info> Activation (enp0s3) successful, device activated.
Jul  :: localhost.localdomain NetworkManager[]: <info> NetworkManager state is now CONNECTED_GLOBAL
Jul  :: localhost.localdomain NetworkManager[]: ifcfg-rh: parsing /etc/sysconfig/network-scripts/ifcfg-lo ...
Jul  :: localhost.localdomain NetworkManager[]: <info> startup complete
Jul  :: localhost.localdomain NetworkManager[]: <warn> Dispatcher script "/etc/NetworkManager/dispatcher.d/20-chrony" failed with timed out: Script '/etc/...imed out.
Jul  :: localhost.localdomain NetworkManager[]: <info> use BlueZ version
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目录/etc/sysconfig下存放网络配置文件和脚本，大多数配置信息存放在该目录下。

文件/etc/sysconfig/network用于全局设置 目录/etc/NetworkManager/system-connections/下存储了VPNs、mobile broadband和PPPoE连接信息

RHEL7中，当手动编辑ifcfg文件的时候，NetworkManager并不会自动意识到所做的更改。

如果手动修改了NetworkManager profile，NetworkManager也不会自动意识到所做的更改。需要重新加载一下配置信息：

#nmcli connection reload

也可以指定被修改的具体文件：

# nmcli con load /etc/sysconfig/network-scripts/ifcfg-eth0

在启动过程中，/etc/init.d/network会读取ifcfg配置文件。

对ONBOOT=yes的配置文件，如果NetworkManager已经启动了对应的设备，就什么都不做。

如果NetworkManager没有启动对应的设备，就使用传统的启动方法，调用ifup来启动设备。