Are there any wire-visible changes to syncprov in the 2.4 series?
Yes.
Specifically, are 2.3 slaves and 2.4 providers expected to interact well?
Yes, if it's a new enough 2.3.
-- -- Howard Chu CTO, Symas Corp. http://www.symas.com Director, Highland Sun http://highlandsun.com/hyc/ Chief Architect, OpenLDAP http://www.openldap.org/project/