Networking 如何在Ubuntu 19.04 VirtualBox虚拟机上实现名称解析？

我在Windows7主机上使用多个VirtualBox Ubuntu 18.10/19.04虚拟机。有一刻，其中一个名字的解析停止了。与互联网的连接仍在工作

ax@buildvm:~$ ping 8.8.8.8
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
64 bytes from 8.8.8.8: icmp_seq=1 ttl=51 time=40.5 ms
64 bytes from 8.8.8.8: icmp_seq=2 ttl=51 time=35.5 ms
64 bytes from 8.8.8.8: icmp_seq=3 ttl=51 time=42.4 ms
64 bytes from 8.8.8.8: icmp_seq=4 ttl=51 time=36.2 ms
^C
--- 8.8.8.8 ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3004ms
rtt min/avg/max/mdev = 35.456/38.635/42.408/2.906 ms
ax@buildvm:~$ ping google.com
ping: google.com: Temporary failure in name resolution

如何使名称解析生效？

---

其他信息

ax@buildvm:~$ ip address show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 08:00:27:fb:bc:af brd ff:ff:ff:ff:ff:ff
    inet 10.0.2.5/24 brd 10.0.2.255 scope global dynamic enp0s3
       valid_lft 947sec preferred_lft 947sec
    inet6 fe80::a00:27ff:fefb:bcaf/64 scope link
       valid_lft forever preferred_lft forever
3: enp0s8: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 08:00:27:27:32:88 brd ff:ff:ff:ff:ff:ff
    inet 192.168.56.106/24 brd 192.168.56.255 scope global dynamic enp0s8
       valid_lft 947sec preferred_lft 947sec
    inet6 fe80::a00:27ff:fe27:3288/64 scope link
       valid_lft forever preferred_lft forever

博客文章提供了解决方案：

$ sudo rm /etc/resolv.conf
$ sudo ln -s /var/run/systemd/resolve/resolv.conf /etc/resolv.conf
$ sudo systemctl restart systemd-resolved.service

我得到了“systemd的作业已解决。服务失败”。我不能做任何其他事情

$ sudo rm /etc/resolv.conf
$ sudo ln -s /var/run/systemd/resolve/resolv.conf /etc/resolv.conf
$ sudo systemctl restart systemd-resolved.service