你能帮我解决这个问题吗？我在这个问题上挣扎了三天多，我无法解决这个问题。
我正在的指导下配置dcos安装https://dcos.io/docs/1.7/administration/installing/custom/advanced/
但不幸的是，我的dcos的dns服务器工作不正常。

1） 下面是nslookup命令的输出：

# nslookup leader.mesos

;; Warning: query response not set
;; Got SERVFAIL reply from 198.51.100.1, trying next server
;; Warning: query response not set
;; Got SERVFAIL reply from 198.51.100.2, trying next server
;; Warning: query response not set
Server:     198.51.100.3
Address:    198.51.100.3#53

**server can't find leader.mesos: SERVFAIL

2） 下面是/opt/mesosphere/etc/mesos-dns.json的输出

{
  "zk": "zk://127.0.0.1:2181/mesos",
  "refreshSeconds": 30,
  "ttl": 60,
  "domain": "mesos",
  "port": 61053,
  "resolvers": ["172.31.0.2"],
  "timeout": 5,
  "listener": "0.0.0.0",
  "email": "root.mesos-dns.mesos",
  "IPSources": ["host", "netinfo"]
}

3） 下面是日志ltl-u dcos mesos dns-b的输出

19:29:50 Authentication failed: EOF
   ***19:29:51 Failed to connect to 127.0.0.1:2181: dial tcp 127.0.0.1:2181: getsockopt: connection refused***
     19:29:52 Connected to 127.0.0.1:2181
     19:29:52 Authenticated: id=98693002200481794, timeout=40000
    service: Main process exited, code=exited, status=1/FAILURE
    service: Unit entered failed state.
    service: Failed with result 'exit-code'.
    7/09/20 19:30:14 generator.go:124: no master
    7/09/20 19:30:14 resolver.go:156: Warning: Error generating records: no master; keeping old DNS state
    7/09/20 19:30:14 main.go:80: master detection timed out after 30s
    service: Service hold-off time over, scheduling restart.
    NS: DNS based Service Discovery.
    DNS: DNS based Service Discovery...
     19:30:19 Connected to 127.0.0.1:2181
     19:30:19 Authenticated: id=98693008095641600, timeout=40000
    DNS: DNS based Service Discovery...
    service: Main process exited,***code=exited, status=2/INVALIDARGUMENT***
    service: Unit entered failed state.
    service: Failed with result 'exit-code'.
    NS: DNS based Service Discovery.
    DNS: DNS based Service Discovery...
     19:39:57 Connected to 127.0.0.1:2181
     19:39:57 Authenticated: id=98693008095641610, timeout=40000
    lines 170-207/207 (END)

请询问是否需要更多日志。。。
非常感谢你！