LDAP with secondary domain controller
Let us say we have a PDC on our domain ad.example.com. SquidGuard authentication query uses something like ldap://192.168.1.1 which is the IP of PDC. If we have a secondary domain controller (setup to serve global catalog and all that) which takes over in case PDC is not available, how squidguard (or any other package/feature) can make use of it?
Will manual DNS entries help? E.g. if we setup a DNS entry for ad.example.com which can be resolved to 192.168.1.1 (the PDC) and 192.168.1.2 (secondary DC), and then change the ldap query URI to ldap://ad.example.com, will it work?
This is a hypothetical question/situation. I don't have any means of testing it at the moment; but I am merely curious if this is the way to do it.