Ubuntu 22.04 指令 CLI 設定網路筆記

有圖形介面之後都被寵壞，完全不知道怎麼透過指令設定網路！在 ubuntu 內有 netplan 也有 Network Manager 管理網路，如果沒有好好設定很容易打架。

預設安裝好 ubuntu 後，應該都會有個檔案 /etc/netplan/00-installer-config.yaml

$ cat /etc/netplan/00-installer-config.yaml
network:
  ethernets:
    eth1:
      dhcp4: true
  version: 2

只要異動 netplan 組態後就要用 下列指令啟用

$ sudo netplan apply

透過下列設定可以手動指定 ip ，不過記得要把 00-installer-config.yaml 更名別的附檔名。

# mv /etc/netplan/00-installer-config.yaml /etc/netplan/00-installer-config.yaml.orig
# cat /etc/netplan/01-custom-ip-config.yaml
network:
  version: 2
  renderer: networkd
  ethernets:
    eth1:
      addresses:
        - 192.168.10.2/24
      nameservers:
        search: [liho.tw, otherdomain]
        addresses: [8.8.8.8, 8.8.4.4]
      routes:
        - to: default
          via: 192.168.10.1

如果要自訂多筆路由可這樣設定

network:
  ethernets:
    eth1:
      #dhcp4: true
      addresses:
      - 172.16.0.2/16
      routes:
      - to: 172.17.0.0/16
        via: 172.16.0.1
      - to: 172.18.0.0/16
        via: 172.16.0.1

這邊會注意到有 renderer 選項 是使用 networkd 理論上應該是使用 systemd-networkd 這個服務。

# systemctl status systemd-networkd
● systemd-networkd.service - Network Configuration
     Loaded: loaded (/lib/systemd/system/systemd-networkd.service; enabled; vendor preset: enabled)
     Active: active (running) since Wed 2022-09-28 17:30:13 CST; 15h ago
TriggeredBy: ● systemd-networkd.socket
       Docs: man:systemd-networkd.service(8)
   Main PID: 1199 (systemd-network)
     Status: "Processing requests..."
      Tasks: 1 (limit: 62941)
     Memory: 2.7M
        CPU: 63ms
     CGroup: /system.slice/systemd-networkd.service
             └─1199 /lib/systemd/systemd-networkd

Sep 28 17:32:14 lala systemd-networkd[1199]: eth1: Link UP

如果是要換成 NetworkManager 也是可以，只要把設定改成下列的描述

# mv /etc/netplan/01-custom-ip-config.yaml /etc/netplan/01-custom-ip-config.yaml.old
# cat /etc/netplan/01-network-manager-all.yaml
network:
  version: 2
  renderer: NetworkManager

改完記得要 netplan apply，還有確認好 NetworkManager 是否有正常啟動

# systemctl start NetworkManager
# systemctl enable NetworkManager
# systemctl status NetworkManager
● NetworkManager.service - Network Manager
     Loaded: loaded (/lib/systemd/system/NetworkManager.service; enabled; vendor preset: enabled)
     Active: active (running) since Wed 2022-09-28 17:32:14 CST; 15h ago
       Docs: man:NetworkManager(8)
   Main PID: 1668 (NetworkManager)
      Tasks: 3 (limit: 62941)
     Memory: 14.6M
        CPU: 369ms
     CGroup: /system.slice/NetworkManager.service
             └─1668 /usr/sbin/NetworkManager --no-daemon

接下來就是透過 nmcli 來設定網路了，用下列方式設定 dhpc 組態

# nmcli con mod eth1 connection.autoconnect yes
# nmcli dev mod eth1 ipv4.method auto
Connection successfully reapplied to device 'eth1'.
# nmcli dev mod eth1 ipv6.method auto
Connection successfully reapplied to device 'eth1'.

檢查一下 eth1 網路狀態

# nmcli device show eth1
GENERAL.DEVICE:                         eth1
GENERAL.TYPE:                           ethernet
GENERAL.HWADDR:                         3C:EC:EF:xx:xx:xx
GENERAL.MTU:                            1500
GENERAL.STATE:                          100 (connected)
GENERAL.CONNECTION:                     eth1
GENERAL.CON-PATH:                       /org/freedesktop/NetworkManager/ActiveConnection/1
WIRED-PROPERTIES.CARRIER:               on
IP4.ADDRESS[1]:                         192.168.10.105/24
IP4.GATEWAY:                            192.168.10.1
IP4.ROUTE[1]:                           dst = 192.168.10.0/24, nh = 0.0.0.0, mt = 101
IP4.ROUTE[2]:                           dst = 0.0.0.0/0, nh = 192.168.10.1, mt = 101
IP4.DNS[1]:                             8.8.8.8
IP4.DNS[2]:                             8.8.4.4
IP4.DOMAIN[1]:                          liho.tw
IP6.ADDRESS[1]:                         fe80::f54b:xxxx:xxxx:xxx/64
IP6.GATEWAY:                            --
IP6.ROUTE[1]:                           dst = fe80::/64, nh = ::, mt = 1024

如果要 connection reload 可以用下列指令：

# nmcli con reload eth1

要看網路狀態可以用下列指令：

# nmcli dev status
DEVICE           TYPE      STATE        CONNECTION
eth1             ethernet  connected    eth1
lo               loopback  unmanaged    --
# nmcli con show
NAME                UUID                                  TYPE      DEVICE
eth1                6a1437da-d884-37cb-b650-ab295639862e  ethernet  eth1
Wired connection 1  eaee1468-6f87-3efe-bdc1-5f315090bc97  ethernet  --
# nmcli con show -a
NAME                UUID                                  TYPE      DEVICE
eth1                6a1437da-d884-37cb-b650-ab295639862e  ethernet  eth1
# nmcli -t device
eth1:ethernet:connected:eth1
lo:loopback:unmanaged:

如果要變更 “Wired connection 1” 為別的名字可以用下列指令：

# nmcli connection modify "Wired connection 1" connection.id xxx
# nmcli con show
NAME             UUID                                  TYPE      DEVICE
eth1             6a1437da-d884-37cb-b650-ab295639862e  ethernet  eth1
xxx              eaee1468-6f87-3efe-bdc1-5f315090bc97  ethernet  --

雖然有點不知道 “Wired connection 1” 是什麼設定 XD 只好把它刪除了

# nmcli con del xxx
Connection 'xxx' (eaee1468-6f87-3efe-bdc1-5f315090bc97) successfully deleted.

假設想要手動指定 ip 可以用下列指令：

# nmcli con mod eth1 ipv4.method manual
# nmcli con mod eth1 ipv4.addresses 192.168.10.2/24
# nmcli con mod eth1 ipv4.gateway 192.168.10.1
# nmcli con mod eth1 ipv4.ignore-auto-dns yes
# nmcli con mod eth1 ipv4.dns "8.8.8.8 8.8.4.4"

假設還有其他額外的設定可以參考下面：

# nmcli con mod eth1 ipv6.method ignore
# nmcli con mod eth1 ipv4.never-default yes
# nmcli con mod eth1 ipv6.never-default yes
# nmcli con mod eth1 802-3-ethernet.mtu 9216
# nmcli con mod eth1 ethernet.mtu 9216
# nmcli con mod eth1 ipv4.method auto
# nmcli con mod eth1 ipv6.method auto
# nmcli con down eth1
# nmcli con up eth1

如果有新的網路介面要設定，那就要用 connection add 指令

# nmcli con add type ethernet ifname ens5f0np0 con-name ens5f0np0
Connection 'ens5f0np0' (43771a64-9bc3-45af-8edd-a71288ac98c1)
successfully added.
# nmcli con add type ethernet ifname ens5f1np1 con-name ens5f1np1
Connection 'ens5f1np1' (8627abac-e7e8-45d3-9344-365dc33ec3e5)
successfully added.

最後入果不想要那麼複雜 就用 nmtui 指令 蠻直覺的 XD

# nmtui