我刚刚安装了一个新的 Ubuntu Server 18.04。我设置了我的主机名hostnamectl set-hostname ****.openbayou.biz并设置了/etc/hosts：
127.0.0.1 localhost
[ip address] ****.openbayou.biz hostname
# The following lines are desirable for IPv6 capable hosts
[ip6 address] *****.openbayou.biz hostname
::1 localhost ip6-localhost ip6-loopback
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
我还安装了 OSSEC 来监控服务器的新文件、错误和更改，现在我收到了这些警报：
Server returned error NXDOMAIN, mitigating potential DNS violation DVE-2018-
0001, retrying transaction with reduced feature level UDP.`
它现在重演：
systemd-resolved[3195]: message repeated 4 times: [ Server returned error
NXDOMAIN, mitigating potential DNS violation DVE-2018-0001, retrying transaction
with reduced feature level …