You would like to specify more than one ldap server to mitigate an outage, right? Not sure if you could specify more than one ip/server for the ldap_server property, probably not. @tmortagne is the expert and can answer this in case this was your question.
There are many ldap implementations that do not support multiple LDAP servers to be specified (or only static). Which is only a question of time until this will no longer work
ActiveDirectory implementations that use SRV records are an exception here. But again, most implementations do not work this way.
You options in this case:
- use a dedicated DNS name like “ldap.myorganisation.com” that has a very short ttl that points to a working LDAP server and manually/automatically update DNS
- use a load balancer (Layer 4 or protocol specific) that will round robin/fail over to a working LDAP server