因为攻击原因UDP协议禁用了后影响到DNS解析了.

echo "options use-vc" >> /etc/resolv.conf

use-vc (since glibc 2.14)
                     Sets RES_USEVC in _res.options.  This option forces
                     the use of TCP for DNS resolutions.

https://man7.org/linux/man-pages/man5/resolv.conf.5.html