My overcloud hasn't access to the Internet and I setting up specific NTP servers (10.10.0.5,10.10.0.6) in our local network in TripleO UI (Edit Configuration -> Parameters -> Base resources configuration). When deploying overcloud, I get an error message that the controller cannot synchronize time.

{
  "msg": "non-zero return code",
  "start": "2019-01-07 06:39:35.553515",
  "stderr": "Error resolving pool.ntp.org: Name or service not known (-2)\n 7 Jan 06:39:35 ntpdate[17812]: Can't find host pool.ntp.org: Name or service not known (-2)\n 7 Jan 06:39:35 ntpdate[17812]: no servers can be used, exiting",
  "stderr_lines": [
    "Error resolving pool.ntp.org: Name or service not known (-2)",
    " 7 Jan 06:39:35 ntpdate[17812]: Can't find host pool.ntp.org: Name or service not known (-2)",
    " 7 Jan 06:39:35 ntpdate[17812]: no servers can be used, exiting"
  ],
  "stdout_lines": [],
  "stdout": "",
  "_ansible_no_log": false,
  "invocation": {
    "module_args": {
      "creates": null,
      "executable": null,
      "_uses_shell": false,
      "_raw_params": "ntpdate -u pool.ntp.org",
      "removes": null,
      "warn": true,
      "chdir": null,
      "stdin": null
    }
  },
  "rc": 1,
  "changed": true,
  "_ansible_parsed": true,
  "delta": "0:00:00.027991",
  "cmd": [
    "ntpdate",
    "-u",
    "pool.ntp.org"
  ],
  "end": "2019-01-07 06:39:35.581506"
}

Why does it use pool.ntp.org? Why doesn't it use 10.10.0.5/10.10.0.6?

I use stable release TripleO Rocky.