Ubuntu18.04 使用ifupdown配置网络

 

https://www.wabks.com/post/615.html

1，安装ifupdown、resolvconf 软件包
apt install ifupdown resolvconf

2, 修改/etc/network/interfaces文件配置网络连接

root@bks:~# cat /etc/network/interfaces
# ifupdown has been replaced by netplan(5) on this system.  See
# /etc/netplan for current configuration.
# To re-enable ifupdown on this system, you can run:
#    sudo apt install ifupdown
auto lo
iface lo inet loopback

auto ens33
iface ens33 inet static
        address 192.168.218.89
        netmask 255.255.255.0
        gateway 192.168.218.2
        dns-nameservers 1.1.1.1 114.114.114.114
3,重启网络接口

ifdown --force ens33 lo && ifup -a
systemctl enable networking
systemctl restart networking
4，停止、取消和禁止 Netplan 相关服务运行，并移除 Netplan 软件包及其配置文件

1,systemd-networkd是 Netplan 后端服务（桌面版则是NetworkManager）；
2,networkd-dispatcher是 Netplan 守护服务，可通过监听连接状态以执行特定事件操作；
3,systemd-networkd-wait-online用于检测systemd-networkd所管理网络接口的连接状态；
4,systemd-resolved新的 DNS 管理服务，其配置文件里有的参数依赖 Netplan 后端服务工作；

systemctl stop systemd-networkd networkd-dispatcher systemd-networkd-wait-online systemd-resolved
systemctl disable systemd-networkd networkd-dispatcher systemd-networkd-wait-online systemd-resolved
systemctl mask systemd-networkd networkd-dispatcher systemd-networkd-wait-online systemd-resolved
apt purge nplan netplan.io

若切换回 Netplan：
将带有 mask 的命令换成 unmask 运行一次，不然即使 start  disable 了也没法使用服务。

apt install nplan netplan.io
systemctl unmask systemd-networkd networkd-dispatcher systemd-networkd-wait-online systemd-resolved
systemctl enable systemd-networkd networkd-dispatcher systemd-networkd-wait-online systemd-resolved
systemctl start systemd-networkd networkd-dispatcher systemd-networkd-wait-online systemd-resolved

拓展命令：
systemctl list-dependencies systemd-networkd --reverse查询指定服务所关联的依赖项；
systemctl list-unit-files --type=masked --all列出/lib/systemd/system下被禁止的服务；
5，若出现dns解析不了

如果 DNS 解析不了，请检查/etc/resolv.conf所链接的文件是否是/run/resolvconf/resolv.conf。如果不是，运行下面命令设置。

ln -sf /run/resolvconf/resolv.conf /etc/resolv.conf