Ubuntu18.04 Server设置静态IP

前言：Ubuntu18.04 server安装成功之后，有分配到ip，可以上网。但是遇到重启路由，Ubuntu server端ip地址可能会变掉。鉴于在局域网内，一般还是选择固定server端ip。

方案：下面有两种方式。ifconfig or ip a查询当前的网卡enp0s31f6，or ens33 ..

• Version >=ubuntu18.04，增加透过netplan来设定固定ip的方式，sudo vim /etc/netplan/01-network-manager-all.yaml(文件名可能不同)，改完保存，然后sudo netplan apply。

# Let NetworkManager manage all devices on this system
network:
  version: 2
  renderer: NetworkManager
  ethernets:
    ens33:
      dhcp4: no
      addresses: [192.168.1.123/24]
      gateway4: 192.168.1.1
      nameservers:
        addresses: [8.8.8.8, 114.114.114.114]

 注意yaml语法格式，：之后要加空格

• Version < ubuntu18.04 (or ubuntu18，这里仅示意Ubuntu18之后有改变，不确定具体的版本)，通过修改/etc/network/interfaces，并配置dns 【将resolved.conf里的DNS注释拿掉，加入需要的dns】，设定完之后，reboot重启，不要单单的/etc/init.d/networking restart，这样不一定起作用。

1. sudo vim /etc/network/interfaces
2. sudo vim /etc/systemd/resolved.conf【修改/etc/resolve.conf不起作用，reboot之后又会被默认值覆盖】

#auto lo
#iface lo inet loopback
auto enp0s31f6
iface enp0s31f6 inet static
address 192.168.1.111  #换成自己的ip address
netmask 255.255.255.0  #换成自己的ip netmask
gateway 192.168.1.1    #换成自己的ip gateway

#  This file is part of systemd.
#
#  systemd is free software; you can redistribute it and/or modify it
#  under the terms of the GNU Lesser General Public License as published by
#  the Free Software Foundation; either version 2.1 of the License, or
#  (at your option) any later version.
#
# Entries in this file show the compile time defaults.
# You can change settings by editing this file.
# Defaults can be restored by simply deleting this file.
#
# See resolved.conf(5) for details

[Resolve]
DNS=8.8.8.8 114.114.114.114
#FallbackDNS=
#Domains=
#LLMNR=no
#MulticastDNS=no
#DNSSEC=no
#Cache=yes
#DNSStubListener=yes

小结：Ubuntu18.04网络配置有些改变，server已经可以采用netplan配置，也挺方便；注意传统的配置ip/dns的方式，有所改变，/etc/resolvconf/resolv.conf.d/base 已经没有了，需要修改/etc/systemd/resolved.conf。

参考：

https://blog.youkuaiyun.com/qq_42975842/article/details/81705244

https://blog.youkuaiyun.com/qq_36937342/article/details/80876385