Understanding UDP 389 portqry error and how to solve this issue:

https://social.technet.microsoft.com/Forums/windowsserver/en-US/a6d07279-6852-4dfb-afc7-f06f5b1034c2/port-389udp?forum=winserverDS

https://social.technet.microsoft.com/Forums/sharepoint/en-US/70e97298-42f3-4908-a55f-a18c28572185/udp-389-ldap-did-not-respond-?forum=winserverDS

Solution: