在日常工作维护时收到客户反馈服务器无法访问网站的问题，经过初期测试发现nslookup命令能够解析DNS地址，但其他命令无法识别resolve配置。

[root@281 ~]# curl www.qq.com
curl: (6) Couldn't resolve host 'www.qq.com'
[root@281 ~]# wget www.qq.com
--2022-11-09 13:39:57--  http://www.qq.com/
Resolving www.qq.com... failed: Name or service not known.
wget: unable to resolve host address `www.qq.com'
[root@281 ~]# nslookup www.qq.com 8.8.8.8
Server:        8.8.8.8
Address:    8.8.8.8#53

Non-authoritative answer:
www.qq.com    canonical name = ins-r23tsuuf.ias.tencent-cloud.net.
Name:    ins-r23tsuuf.ias.tencent-cloud.net
Address: 42.81.176.157
Name:    ins-r23tsuuf.ias.tencent-cloud.net
Address: 42.81.179.153

解决办法

如果在网卡配置中未配置DNS信息，则需手动配置DNS信息。

通过排查，是由于NetworkManager服务未启动导致的问题，启动服务后恢复正常。

[root@281 ~]# service NetworkManager status
NetworkManager is stopped
[root@281 ~]# service NetworkManager start 
Setting network parameters...                              [  OK  ]
Starting NetworkManager daemon:                            [  OK  ]