先用ifconfg查询网卡名称
例如以下的是enp10s0
enp10s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.100.159  netmask 255.255.255.0  broadcast 192.168.100.255
        inet6 fe80::127c:61ff:fe4c:ab6b  prefixlen 64  scopeid 0x20<link>
        ether 10:7c:61:4c:ab:6b  txqueuelen 1000  (Ethernet)
        RX packets 6944  bytes 5404329 (5.4 MB)
        RX errors 0  dropped 16  overruns 0  frame 0
        TX packets 6190  bytes 969425 (969.4 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
        
        
2. 修改conifg
        sudo nano /etc/netplan/00-installer-config.yaml
   写入：
           
network:
  version: 2
  renderer: networkd
  ethernets:
    enp10s0:
      dhcp4: false
      addresses:
        - 192.168.100.10/24
      gateway4: 192.168.100.1



-----------------------------
这是改为192.168.100.10的范例
ctrl+X 保存后退出



3. sudo netplan apply


改为后可能上不了网，如果要改回来
修改dhcp4为true
dhcp4: true
然后 sudo netplan apply即可