Steps to reproduce:

1. Have two ldap servers, ldap1.domain.tld and ldap2.domain.tld with A records.
2. Use a DNS address such as ldaphosts.domain.tld.  This should point to to the A records for ldap1/2.
3. Attempt to configure LDAP authentication using ldaphosts.domain.tld
4. LDAP binding fails.
5. Change ldap host to the hostname of a single LDAP host (such as ldap1.domaint.tld) and LDAP binding works.

Result:
Expect that we can use a DNS address to use CNAME, A or AAAA records to multiple LDAP capable servers and be able to bind to any of them.  Providing Highly Availability for LDAP binding.
Expected:
Binding fails.

 

I am using Active Directory on Server 2019.  I can get LDAP binding by pointing to any domain controller in my environment by hostname.  However if I try to use a custom DNS address with the A records pointing to all Active Directory systems accessible to the zabbix server, it fails to bind.

The end result is we can bind to any LDAP capable server or be able to specify a backup LDAP bind server.