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关于Linux中网络连接配置(NetworkManager)的一些笔记

热度:36   发布时间:2024-01-13 07:40:27.0

写在前面


  • 嗯,准备RHCA,学习整理这部分知识
  • NetworkManager其实是RHCAS的内容
  • 博文内容为常见的配置操作回顾:
    • NetworkManager简述
    • 命令行的方式配置网络连接
    • 修改配置文件的方式配置网络连接
    • 谁有权限修改网络连接配置

傍晚时分,你坐在屋檐下,看着天慢慢地黑下去,心里寂寞而凄凉,感到自己的生命被剥夺了。当时我是个年轻人,但我害怕这样生活下去,衰老下去。在我看来,这是比死亡更可怕的事。--------王小波


红帽8(rhel8,Centos 8)使用的网络管理服务有两个:NetworkManagernetworkrhel8默认使用NetworkManager服务管理网络。如果要使用network,需要单独启动服务处理,network的启动是通过之前的init文件来引导的。

常见的配置网络方法:

  • 通过nmcli connection add命令配置,会自动生成ifcfg文件
  • 手动配置ifcfg-name文件,通过nmcli connection reload来加载生效。
  • 手动配置ifcfg-name文件,通过旧服务network.service来加载生效。
  • 通过nmtui 以图形化的方式配置

不管那种方式,基本都是就围绕NetworkManager服务展开,除了使用旧的服务单元network.service

┌──[root@liruilongs.github.io]-[~]
└─$systemctl status NetworkManager
● NetworkManager.service - Network ManagerLoaded: loaded (/usr/lib/systemd/system/NetworkManager.service; enabled; vendor preset: enabled)Active: active (running) since Mon 2022-04-11 21:10:36 CST; 1h 24min agoDocs: man:NetworkManager(8)Main PID: 1139 (NetworkManager)Tasks: 3 (limit: 37720)Memory: 8.9MCGroup: /system.slice/NetworkManager.service└─1139 /usr/sbin/NetworkManager --no-daemonApr 11 22:12:28 liruilongs.github.io NetworkManager[1139]: <info>  [1649686348.7137] device (vnet1): Activation: starti>
....

NetworkManager简述

基于NetworkManager的系统守护进程,主要负责管理网络接口(device)连接配置(connection)。它监视管理网络设置,并使用/etc/sysconfig/networkscripts/目录中的文件来存储它们。

NetworkManager中,设备是网络接口连接是可以为设备配置的设置的集合。任何设备在同一时间只有一个连接是活动的。可能存在多个连接,用于不同设备的使用,或者允许对同一设备的配置进行更改。

每个连接都有一个名称或ID来标识它。/etc/sysconfig/network-scripts/ifcfg-name文件存储连接的持久配置,其中name是连接的名称。当连接名中有空格时,文件名中的空格将被替换为下划线。如果需要,这个文件可以手工编辑。

nmcli程序从shell提示符创建和编辑连接文件。

查看组网信息,可以通过nmcli dev status命令用来查看所有网络设备的当前状态。

┌──[root@liruilongs.github.io]-[~]
└─$nmcli dev status
DEVICE      TYPE      STATE      CONNECTION
privbr0     bridge    connected  privbr0
virbr0      bridge    connected  virbr0
eth0        ethernet  connected  eth0
vnet0       tun       connected  vnet0
vnet1       tun       connected  vnet1
lo          loopback  unmanaged  --
virbr0-nic  tun       unmanaged  --

当然nmcli操作除dev和con之外其他一些对象,暂时不清楚是干什么的,以后有机会研究下。

┌──[root@liruilongs.github.io]-[~]
└─$nmcli
agent       connection  device      general     help        monitor     networking  radio

nmcli con show命令用来显示所有连接的列表。添加--active选项来只列出活动的连接。

┌──[root@liruilongs.github.io]-[~]
└─$nmcli con show --active
NAME     UUID                                  TYPE      DEVICE
privbr0  ef4e7961-d070-920c-71d7-51d86377d921  bridge    privbr0
virbr0   667e5abb-da79-4c74-b4d6-dc203a14948c  bridge    virbr0
eth0     5fb06bd0-0bb0-7ffb-45f1-d6edd65f3e03  ethernet  eth0
vnet0    d801c759-2775-4a4c-8694-85adb30af9db  tun       vnet0
vnet1    a33cf39d-c485-40d3-affd-6fed087fbbe8  tun       vnet1
┌──[root@liruilongs.github.io]-[~]
└─$

device

device即网卡设备。常用的命令如下

┌──[root@servera.lab.example.com]-[~]
└─$nmcli device
connect     disconnect  lldp        monitor     set         status
delete      help        modify      reapply     show        wifi

关于device,一般不怎么操作,通过show命令 nmcli device show eth0可以查看网卡详细信息

┌──[root@servera.lab.example.com]-[~]
└─$nmcli device show eth0
GENERAL.DEVICE:                         eth0
GENERAL.TYPE:                           ethernet
GENERAL.HWADDR:                         52:54:00:00:FA:0A
GENERAL.MTU:                            1500
GENERAL.STATE:                          100 (connected)
GENERAL.CONNECTION:                     Wired connection 1
GENERAL.CON-PATH:                       /org/freedesktop/NetworkManager/ActiveConnection/1
WIRED-PROPERTIES.CARRIER:               on
IP4.ADDRESS[1]:                         172.25.250.10/24
IP4.GATEWAY:                            172.25.250.254
IP4.ROUTE[1]:                           dst = 172.25.250.0/24, nh = 0.0.0.0, mt = 100
IP4.ROUTE[2]:                           dst = 0.0.0.0/0, nh = 172.25.250.254, mt = 100
IP4.DNS[1]:                             172.25.250.254
IP6.ADDRESS[1]:                         fe80::984:87d2:dba7:1007/64
IP6.GATEWAY:                            --
IP6.ROUTE[1]:                           dst = fe80::/64, nh = ::, mt = 100
IP6.ROUTE[2]:                           dst = ff00::/8, nh = ::, mt = 256, table=255
┌──[root@servera.lab.example.com]-[~]
└─$

connection

connection 即为添加动态网络连接配置,常用的命令如下

┌──[root@servera.lab.example.com]-[~]
└─$nmcli connection
add      delete   edit     help     load     monitor  show
clone    down     export   import   modify   reload   up
查看show

通过nmcli connection show可以查看网络配置的详细信息

┌──[root@servera.lab.example.com]-[~]
└─$nmcli connection show
NAME                UUID                                  TYPE      DEVICE
Wired connection 1  4ae4bb9e-8f2d-3774-95f8-868d74edcc3c  ethernet  eth0
Wired connection 2  c0e6d328-fcb8-3715-8d82-f8c37cb42152  ethernet  --
Wired connection 3  9b5ac87b-572c-3632-b8a2-ca242f22733d  ethernet  --
添加add

通过 nmcli connection add 添加一个网络连接,默认IP为动态获取

┌──[root@servera.lab.example.com]-[~]
└─$nmcli connection add type ethernet con-name dynamic-eth1 ifname eth1
Connection 'dynamic-eth1' (91575fc2-a151-4da4-a174-757b4bf9c483) successfully added.

这里添加的网络配置名字为dynamic-eth1,使用的网卡为eth1,查看添加的网络连接配置

┌──[root@servera.lab.example.com]-[~]
└─$nmcli connection show
NAME                UUID                                  TYPE      DEVICE
Wired connection 2  c0e6d328-fcb8-3715-8d82-f8c37cb42152  ethernet  eth1
Wired connection 3  9b5ac87b-572c-3632-b8a2-ca242f22733d  ethernet  eth2
Wired connection 1  4ae4bb9e-8f2d-3774-95f8-868d74edcc3c  ethernet  eth0
dynamic-eth1        91575fc2-a151-4da4-a174-757b4bf9c483  ethernet  --

这里IP地址获取方式默认为动态获取

┌──[root@servera.lab.example.com]-[~]
└─$nmcli connection show  dynamic-eth1 | grep ipv4.m
ipv4.method:                            auto
ipv4.may-fail:                          yes

添加一个连接,网络类型配置为因特网(ethernet)

┌──[root@servera.lab.example.com]-[~]
└─$nmcli connection add con-name static ifname eth1 type ethernet
Connection 'static' (1833628a-ebe3-4fd0-9be1-9bed877067c9) successfully added.
修改modify

nmcli con mod name命令用于修改连接设置。这些更改也保存在连接的/etc/sysconfig/network-scripts/ifcfg-name文件中。

┌──[root@servera.lab.example.com]-[~]
└─$nmcli connection modify static  +ipv4.dns 114.114.114.114
┌──[root@servera.lab.example.com]-[~]
└─$nmcli connection show static | grep ipv4.dn
ipv4.dns:                               172.25.25.254,114.114.114.114
ipv4.dns-search:                        --
ipv4.dns-options:                       --
ipv4.dns-priority:                      0

修改ipv4的IP地址获取方式为手动,并指定IP地址、网关、DNS

┌──[root@servera.lab.example.com]-[~]
└─$nmcli connection modify static ipv4.method  manual ipv4.addresses  172.25.25.10/24 ipv4.gateway 172.25.25.254 ipv4.dns 172.25.25.254

查看系修改后的信息,切记修改完需要从新激活

┌──[root@servera.lab.example.com]-[~]
└─$nmcli connection show static | grep ipv4
ipv4.method:                            manual
ipv4.dns:                               172.25.25.254
ipv4.dns-search:                        --
ipv4.dns-options:                       --
ipv4.dns-priority:                      0
ipv4.addresses:                         172.25.25.10/24
ipv4.gateway:                           172.25.25.254
ipv4.routes:                            --
ipv4.route-metric:                      -1
ipv4.route-table:                       0 (unspec)
ipv4.routing-rules:                     --
ipv4.ignore-auto-routes:                no
ipv4.ignore-auto-dns:                   no
ipv4.dhcp-client-id:                    --
ipv4.dhcp-timeout:                      0 (default)
ipv4.dhcp-send-hostname:                yes
ipv4.dhcp-hostname:                     --
ipv4.dhcp-fqdn:                         --
ipv4.never-default:                     no
ipv4.may-fail:                          yes
ipv4.dad-timeout:                       -1 (default)
┌──[root@servera.lab.example.com]-[~]
└─$
激活up

nmcli con up name命令用来激活绑定了名称连接的网络接口。该命令使用连接名,而不是网络接口名,下面执行可以动态获取ip

┌──[root@servera.lab.example.com]-[~]
└─$nmcli connection up static
Connection successfully activated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/288)
断开disconnect

nmcli dev disconnect device命令用来断开设备的网络接口,使其断开。命令缩写为nmcli dev dis device

┌──[root@servera.lab.example.com]-[~]
└─$nmcli dev dis dynamic-eth1

这里需要说明的是,nmcli con down name命令通常不是禁用网络接口的最佳方法,因为它会导致连接中断。然而,默认情况下,大多数有线系统连接配置为启用自动连接。这将在网络接口可用时立即激活连接。因为连接的网络接口仍然是可用的,nmcli con down name会将该接口关闭,但随后NetworkManager会立即将其打开,除非该连接与该接口完全断开。

删除delete
┌──[root@servera.lab.example.com]-[~]
└─$nmcli connection delete dynamic-eth1
Connection 'dynamic-eth1' (91575fc2-a151-4da4-a174-757b4bf9c483) successfully deleted.

配置文件

网络连接配置中,静态连接属性保存在/etc/sysconfig/network-scripts/ifcfg-*配置文件中。

动态的连接数据,如设置IP自动获取,即从DHCP服务器获得的,是不持久存储的。

执行nmcli con show name命令查询连接的当前设置。小写设置是可以更改的静态属性大写设置是连接实例临时使用动态设置

┌──[root@liruilongs.github.io]-[~]
└─$nmcli con show vnet0
connection.id:                          vnet0
connection.uuid:                        d801c759-2775-4a4c-8694-85adb30af9db
connection.stable-id:                   --
connection.type:                        tun
connection.interface-name:              vnet0
...................
GENERAL.NAME:                           vnet0
GENERAL.UUID:                           d801c759-2775-4a4c-8694-85adb30af9db
GENERAL.DEVICES:                        vnet0
GENERAL.IP-IFACE:                       vnet0
GENERAL.STATE:                          activated
......
配置文件信息查看
┌──[root@servera.lab.example.com]-[~]
└─$cd /etc/sysconfig/network-scripts/
┌──[root@servera.lab.example.com]-[/etc/sysconfig/network-scripts]
└─$cat ifcfg-static
TYPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=none
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=no
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
IPV6_ADDR_GEN_MODE=stable-privacy
NAME=static
UUID=1833628a-ebe3-4fd0-9be1-9bed877067c9
DEVICE=eth1
ONBOOT=yes
IPADDR=172.25.25.10
PREFIX=24
GATEWAY=172.25.25.254
DNS1=172.25.25.254
IPV6_DISABLED=yes
DNS2=114.114.114.114
┌──[root@servera.lab.example.com]-[/etc/sysconfig/network-scripts]
└─$

配置文件修改后需要从新加载激活

┌──[root@servera.lab.example.com]-[/etc/sysconfig/network-scripts]
└─$nmcli connection reload
┌──[root@servera.lab.example.com]-[/etc/sysconfig/network-scripts]
└─$nmcli connection up static
Connection successfully activated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/290)
┌──[root@servera.lab.example.com]-[/etc/sysconfig/network-scripts]
└─$

谁可以修改网络设置

修改网络配置的权限:root和以及本地登录的普通用户可以修改,通过SSH远程的普通用户没有权限

  • ROOT
┌──[root@liruilongs.github.io]-[~]
└─$nmcli general permissions
PERMISSION                                                        VALUE
org.freedesktop.NetworkManager.enable-disable-network             yes
org.freedesktop.NetworkManager.enable-disable-wifi                yes
org.freedesktop.NetworkManager.enable-disable-wwan                yes
org.freedesktop.NetworkManager.enable-disable-wimax               yes
org.freedesktop.NetworkManager.sleep-wake                         yes
org.freedesktop.NetworkManager.network-control                    yes
org.freedesktop.NetworkManager.wifi.share.protected               yes
org.freedesktop.NetworkManager.wifi.share.open                    yes
org.freedesktop.NetworkManager.settings.modify.system             yes
org.freedesktop.NetworkManager.settings.modify.own                yes
org.freedesktop.NetworkManager.settings.modify.hostname           yes
org.freedesktop.NetworkManager.settings.modify.global-dns         yes
org.freedesktop.NetworkManager.reload                             yes
org.freedesktop.NetworkManager.checkpoint-rollback                yes
org.freedesktop.NetworkManager.enable-disable-statistics          yes
org.freedesktop.NetworkManager.enable-disable-connectivity-check  yes
org.freedesktop.NetworkManager.wifi.scan                          unknown
  • 本地登录的普通用户

在这里插入图片描述

  • 远程登录的普通用户
[liruilong@liruilongs /]$nmcli general permissions
PERMISSION                                                        VALUE
org.freedesktop.NetworkManager.enable-disable-network             no
org.freedesktop.NetworkManager.enable-disable-wifi                no
org.freedesktop.NetworkManager.enable-disable-wwan                no
org.freedesktop.NetworkManager.enable-disable-wimax               no
org.freedesktop.NetworkManager.sleep-wake                         no
org.freedesktop.NetworkManager.network-control                    auth
org.freedesktop.NetworkManager.wifi.share.protected               no
org.freedesktop.NetworkManager.wifi.share.open                    no
org.freedesktop.NetworkManager.settings.modify.system             auth
org.freedesktop.NetworkManager.settings.modify.own                auth
org.freedesktop.NetworkManager.settings.modify.hostname           auth
org.freedesktop.NetworkManager.settings.modify.global-dns         auth
org.freedesktop.NetworkManager.reload                             auth
org.freedesktop.NetworkManager.checkpoint-rollback                auth
org.freedesktop.NetworkManager.enable-disable-statistics          no
org.freedesktop.NetworkManager.enable-disable-connectivity-check  no
org.freedesktop.NetworkManager.wifi.scan                          unknown
[liruilong@liruilongs /]$