How to configure FreeRADIUS with multiple ldap servers?

Question

I have a FreeRADIUS server that uses ldap as as a storage backend for its users. They are both located on the same machine running UBUNTU Linux 12.04 LTS.

Now I would like to set up another ldap server on another machine to add redundancy so that I could use it in case of my local ldap server's failure. Can anyone tell me how I can do it? Nothing is mentioned in RADIUS configuration files regarding multiple ldap servers.

The same question applies to Samba.

Any help would be greatly appreciated.

Answer 1

This is actually pretty easy, you can just list multiple servers here in the LDAP configuration, separated by commas.

libldap takes care of the rest.

Edit: For later versions of FreeRADIUS 3 the LDAP module expects multiple instances of the server config item. For example:

server = 'ldap1.example.org'
server = 'ldap2.example.org'
server = 'ldap3.example.org'

This is so internally, when the module is rewriting the URIs, they're already broken out into separate strings, which makes the code easier. It also looks a bit cleaner.