正在运行 Raise 网络接口的停止作业 (/1min 31s)

Question

当我尝试关闭运行 ubuntu 16.04.5 的电脑时，它会挂在这条线上：

A stop job is running for Raise network interfaces (1s/1min 31s)

这是我的 /etc/network/interfaces 文件：

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

source /etc/network/interfaces.d/*

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
allow-hotplug enp0s31f6
iface enp0s31f6 inet dhcp

我添加了 allow-hotplug 因为我在启动时遇到另一个错误

A start job is running for Raise network interfaces (1s/5min 2s)

有人可以帮我解决这个问题吗？

感谢您的任何帮助。