Will prldap_init() do any DNS query?

Hi, all: 

I am just thinking of a question.

If the first parameter to be passed into prldap_init() is a hostname, when will DNS resolve it to IP address? Will DNS query happens in ldap_simple_bind_s() in case of simple binding, and in ldap_sasl_interactive_bind_ext_s() in case of sasl binding, or it just happens in prldap_init()?

Thanks,
Xu Qiang