This option can be set to a string describing the TLS protocols to be supported in the parts of Samba that use GnuTLS, specifically the AD DC. The string is appended to the default priority list of GnuTLS. The valid options are described in the GNUTLS Priority-Strings documentation at http://gnutls.org/manual/html_node/Priority-Strings.html The SSL3.0 protocol will be disabled. NORMAL:-VERS-SSL3.0