rootdn for syncrepl?

[Maykel Moya <moya-lists@infomed.sld.cu>]

In man slapd.conf you can read:

--
rootdn <dn>
  Specify the distinguished name that is not subject to access control
  or administrative limit restrictions for operations on this 
  database.
  [...]
  Note that the rootdn is always needed when using syncrepl.
--

In this Conexitor forum[1] about replication configuration a particular
DN is used with permissions granted via ACIs, it seems that
cn=replicator is not the rootdn.

Could you clarify about the real necessity of rootdn (and its usage) for
syncrepl?

Regards,
maykel

[1] http://www.connexitor.com/forums/viewtopic.php?t=3