Are there any enterprise-grade services for externally hosted LDAP used for authenticating users in our company?
Internally, we have many development and test servers that have system users locally created, and then we connect to our current LDAP directory in order to authenticate users. We have many other services that leverage this as well.
We no longer have an individual we feel qualified to manage our LDAP directory, and currently do not want to invest the time nor the resources to get back up to where we were previously. (And, I'm trying to prevent the "cure-all" NIS/YP coming back into play.)
I'm looking for a company that provides an LDAP instance, reliable (duh), good tools for managing users, groups, and really the DN as a whole. Ideally, they support synchronization so we can have a trivial setup in-house that lives off replication, and can be used by our local servers for fast(er) queries for logins and the like, with the secondary fallback to the external system.
While I would prefer to stick with an OpenLDAP based service, I'm open to alternatives that "speak" standard LDAP, and can be used with all the LDAP tools already available (Linux PAM LDAP Auth, mod_authnz_ldap for Apache, etc.). I am not interested in switching to Active Directory.
[edit]
Additionally, this is preferably an offsite host. Not an appliance or anything that we'll buy and place in our facility. The option to have an appliance on-site in addition to the remote host for the replication reason I gave previously is an interesting option, if such a thing exists.
[edit2]
An additional thought occurred to me earlier today. Are there any primary service hosts out there (e-mail hosts, corporate messaging hosts [preferably XMPP], etc.) that would as a result of hosting this function, also expose an LDAP instance? One that they officially support?
It would be very nice if the replication appliance I talked about in my first edit still applies here.