220.127.116.11.1.11 LDAP Search Over UDP
Active Directory supports search over UDP only for searches against rootDSE. It encodes the results of an LDAP search performed over UDP in the same manner as it does a search performed over TCP; specifically, as one or more SearchResultEntry messages followed by a SearchResultDone message, as described in [RFC2251]. This means that the search response is not encoded as described in [RFC1798]. Only LDAP search and LDAP abandon operations are supported over UDP by Active Directory.