A listener for an unspecified IPv6 address accepts both IPv4 and IPv6 connections on Linux. Because of this behavior, Linux does not allow you to start both IPv4 and IPv6 unspecified listeners for the same port at the same time. Therefore; if a listener is already configured for an unspecified IPv6 address, the listener on the unspecified IPv4 address fails to start. Linux uses an unspecified address for LDAP listeners.
NOTE:On a SLES 10 computer, if an IPv4 unspecified listener is already there, then IPv6-specific IP listeners for the same port does not start. This is a known issue with SLES 10. However, SLES 11 does not have this issue.
On Windows, an unspecified IPv6 listener accepts only IPv6 connections. Therefore, you must configure a separate IPv4 listener to accept IPv4 connections along with IPv6 connections.
By default, both IPv4 and IPv6 listeners are configured for ldapInterfaces. Depending on the platform, ldapInterfaces starts the required listeners.