VanStaub 120000BGUR Visits (3216)
At one time, we had three LDAP vendors (Domino LDAP, IBM Directory Server, and Active Directory) paired with its own Portal server. QuickPlace and Sametime were then paired with a respective Portal and LDAP server. All in all, at a minimum that makes 15 servers.
To consolidate, we use Portal LDAP federation. The Portal Infocenter makes a fair attempt at explaining this; however, I find the following technote much more helpful: How to configure WebSphere Portal for multiple LDAP servers. This allows us to use three versions of Portal federated to three LDAP servers.
Technically, you can further reduce the configuration overhead by federating the three LDAPs to QuickPlace by configuring QuickPlace to use Domino directory for authentication and setting up directory assistance to the various LDAP servers. The Sametime server's stconfig.nsf databases's LDAP documents can be copied to federate the LDAP servers with Sametime. Be aware that if you copy the LDAP documents, they should point to different LDAP server FQDNs. The LDAP servers can physically reside on the same server, but you should set up DNS or local hosts files to separate them out as ldap1.ibm.com, ldap2.ibm.com, ldapN.ibm.com. I assume that Sametime stores the LDAP settings using the LDAP FQDN as a key so multiple documents with the same FQDN will overwrite each other.
We tried the above QuickPlace and Sametime configurations with some success but eventually opted to use a single IDS LDAP. Ultimately, you do want to keep the environment as simple as possible if you can. This always limits the likelihood of a "less than tested" issue from arising. But if you're pressed for space, servers, or the adventureous type, some form of federation may assist you in server consolidation.