我想使用笔记本上的读卡器，但是驱动只有 5.x 的支持，因此想安装 Ubuntu lts 设置设备直通，但是卡在第一步，虚拟机无法联网。全部默认配置，使用默认的 ‘default’: NAT，但是无法虚拟机内无法联网 
。
有遇到同样问题的吗？ 我还试了 cachyos 上的 virt-manager 默认配置一样无法联网，但是能 ping bing.com 可以 ping 通。
cat /etc/resolv.conf 看看。
Ubuntu 上好像是被 systemd 管理的
ubuntu@ubuntu:~$ cat /etc/resolv.conf
# This is /run/systemd/resolve/stub-resolv.conf managed by man:systemd-resolved(8).
# Do not edit.
#
# This file might be symlinked as /etc/resolv.conf. If you're looking at
# /etc/resolv.conf and seeing this text, you have followed the symlink.
#
# This is a dynamic resolv.conf file for connecting local clients to the
# internal DNS stub resolver of systemd-resolved. This file lists all
# configured search domains.
#
# Run "resolvectl status" to see details about the uplink DNS servers
# currently in use.
#
# Third party programs should typically not access this file directly, but only
# through the symlink at /etc/resolv.conf. To manage man:resolv.conf(5) in a
# different way, replace this symlink by a static file or a different symlink.
#
# See man:systemd-resolved.service(8) for details about the supported modes of
# operation for /etc/resolv.conf.
nameserver 127.0.0.53
options edns0 trust-ad
search .
虽然不能联网但是我可以 ping 通， 貌似是因为虚拟机总是会使用 ipv6
ubuntu@ubuntu:~$ ping bing.com
PING bing.com (150.171.28.10) 56(84) bytes of data.
64 bytes from 150.171.28.10 (150.171.28.10): icmp_seq=1 ttl=109 time=78.3 ms
64 bytes from 150.171.28.10 (150.171.28.10): icmp_seq=2 ttl=109 time=79.5 ms
64 bytes from 150.171.28.10 (150.171.28.10): icmp_seq=3 ttl=109 time=80.2 ms
64 bytes from 150.171.28.10 (150.171.28.10): icmp_seq=4 ttl=109 time=81.2 ms
^C
--- bing.com ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3005ms
rtt min/avg/max/mdev = 78.288/79.785/81.159/1.045 ms
ubuntu@ubuntu:~$
这是 apt update 的情况，无法工作，我这里运营商并没有 ipv6
那你 resolvectl 看看。
ubuntu@ubuntu:~$ resolvectl status
Global
Protocols: -LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
resolv.conf mode: stub
Link 2 (enp1s0)
Current Scopes: DNS
Protocols: +DefaultRoute +LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
Current DNS Server: 192.168.122.1
DNS Servers: 192.168.122.1
ubuntu@ubuntu:~$
这个地址你 ping 得通吗？dig @192.168.122.1 www.baidu.com 能成功吗？
你的 nameserver 为什么是这个？这明显不对啊。
systemd-resolved 的监听地址就是这个