我的docker配置了默认的域名服务器，但是运行后能够ping通ip地址，却不能ping通域名站点。该怎么办？
$ ps -ef | grep docker
root 1130 1 0 17:32 ? 00:00:10 /usr/bin/docker daemon -H fd:// --dns=61.139.2.69 --registry-mirror=https://44mfwmrx.mirror.aliyuncs.com
$ docker run -it --dns=61.139.2.69 centos
[root@c3b7344feace /]# ping 61.135.169.125
PING 61.135.169.125 (61.135.169.125) 56(84) bytes of data.
64 bytes from 61.135.169.125: icmp_seq=1 ttl=54 time=46.1 ms
64 bytes from 61.135.169.125: icmp_seq=2 ttl=54 time=45.2 ms
64 bytes from 61.135.169.125: icmp_seq=3 ttl=54 time=45.7 ms
^C
--- 61.135.169.125 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2002ms
rtt min/avg/max/mdev = 45.246/45.686/46.109/0.393 ms
[root@c3b7344feace /]# ping -c 2 www.baidu.com
ping: unknown host www.baidu.com
