For LDAP over SSL to work we need the LDAP servers public certificate. This you can either get from the LDAP server admin or by the following process.
Turn you browser towards the LDAP server, remember to use HTTPS when connecting to the LDAP server.
If you browser don't trust the certificate of the LDAP server, click on the continuew to this website link.
choose view certificate, by clicking on the box called Certificate Error and the in the popup that appears below click View certificates.
choose Details in the certificate box.
click on Copy to File..., this will start the Certificate Export Wizard.
Click Next
choose DER encoded binary X.509 and click on Next.
choose a file to export the certificate and click Next.
Click Finish
Click OK.