tags:
  - error

虚拟机17导入旧镜像，ping baidu.com报错：Temporary failure in name resolution，但是ping ip，比如ping 8.8.8.8却正常。
修改/etc/resolv.conf，添加nameserver是不起作用的。

ubuntu22

尝试用resolvectl修改接口的dns服务器地址
这是出现Temporary failure in name resolution的状态：

$ sudo resolvectl status
Global
       Protocols: -LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
resolv.conf mode: stub

Link 2 (ens33)
    Current Scopes: DNS
         Protocols: +DefaultRoute +LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
Current DNS Server: 192.168.145.2
       DNS Servers: 192.168.145.2
        DNS Domain: localdomain

Link 3 (docker0)
Current Scopes: none
     Protocols: -DefaultRoute +LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported

修改为1.1.1.1

sudo resolvectl dns ens33 1.1.1.1

这是ping一下，是可以ping通的，但是延迟很高。(别急着去操作，看完后面！！！)

ping baidu.com
PING baidu.com (39.156.66.10) 56(84) bytes of data.
64 bytes from 39.156.66.10: icmp_seq=1 ttl=128 time=48.3 ms
64 bytes from 39.156.66.10: icmp_seq=2 ttl=128 time=42.4 ms
64 bytes from 39.156.66.10 (39.156.66.10): icmp_seq=3 ttl=128 time=42.8 ms
64 bytes from 39.156.66.10: icmp_seq=4 ttl=128 time=42.3 ms
64 bytes from 39.156.66.10: icmp_seq=5 ttl=128 time=41.9 ms
^C64 bytes from 39.156.66.10: icmp_seq=6 ttl=128 time=43.7 ms

--- baidu.com ping statistics ---
6 packets transmitted, 6 received, 0% packet loss, time 45583ms
rtt min/avg/max/mdev = 41.931/43.559/48.250/2.171 ms

换成其他dns服务器又不行，换回1.1.1.1也不行。

下面是NAT-网络拓扑结构图，对应我的虚拟机环境，虚拟网卡地址是192.168.145.1，虚拟交换机是192.168.145.2

用nmap扫描192.168.145.2（虚拟交换机）发现53端口是开的，也就是默认就应该由这个地址来充当域名解析。

最后的操作

升级虚拟机。由于镜像是用的之前16版本的，现在的是17，所以点了升级虚拟机。(注意升级后的虚拟机不会向下兼容)
虚拟网络编辑器，NAT模式，还原默认设置。

当前配置

Ubuntu：

$sudo resolvectl status
Global
       Protocols: -LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
resolv.conf mode: stub

Link 2 (ens33)
    Current Scopes: DNS
         Protocols: +DefaultRoute +LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
Current DNS Server: 192.168.239.2
       DNS Servers: 192.168.239.2
        DNS Domain: localdomain

Link 3 (docker0)
Current Scopes: none
     Protocols: -DefaultRoute +LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported

/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 localdomain

/etc/hosts

127.0.0.1	localhost
127.0.1.1	zsc

# The following lines are desirable for IPv6 capable hosts
::1     ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters

kali:
kali上没有resolvectl，需要手动安装——

sudo apt install systemd-resolved

也可以使用其他命令查看相关信息：

nmcli dev show
ip addr show
ip route show

resolvectl status:

$ sudo resolvectl status
Global
         Protocols: +LLMNR +mDNS -DNSOverTLS DNSSEC=no/unsupported
  resolv.conf mode: stub

Link 2 (eth0)
    Current Scopes: DNS LLMNR/IPv4 LLMNR/IPv6 mDNS/IPv4 mDNS/IPv6
         Protocols: +DefaultRoute +LLMNR +mDNS -DNSOverTLS DNSSEC=no/unsupported
       DNS Servers: 192.168.239.2
        DNS Domain: localdomain

/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 localdomain

/etc/hosts

127.0.0.1       localhost                                                                       127.0.1.1       kali                                                                            ::1             localhost ip6-localhost ip6-loopback                                            ff02::1         ip6-allnodes                                                                    ff02::2         ip6-allrouters