diff --git a/source4/cldap_server/netlogon.c b/source4/cldap_server/netlogon.c
index ce49f084f82..252ae884ea4 100644
--- a/source4/cldap_server/netlogon.c
+++ b/source4/cldap_server/netlogon.c
@@ -33,6 +33,7 @@
 static NTSTATUS cldapd_netlogon_fill(struct cldap_socket *cldap,
 				     TALLOC_CTX *mem_ctx,
 				     const char *domain,
+				     const char *domain_guid,
 				     const char *user,
 				     const char *src_address,
 				     uint32_t version,
@@ -61,13 +62,15 @@ static NTSTATUS cldapd_netlogon_fill(struct cldap_socket *cldap,
 	}
 
 	/* the domain has an optional trailing . */
-	if (domain[strlen(domain)-1] == '.') {
+	if (domain && domain[strlen(domain)-1] == '.') {
 		domain = talloc_strndup(mem_ctx, domain, strlen(domain)-1);
 	}
 
 	/* try and find the domain */
 	ret = gendb_search(samctx, samctx, NULL, &res, attrs, 
-			   "(&(dnsDomain=%s)(objectClass=domainDNS))", domain);
+			   "(&(objectClass=domainDNS)(|(dnsDomain=%s)(objectGUID=%s)))", 
+			   domain?domain:"", 
+			   domain_guid?domain_guid:"");
 	if (ret != 1) {
 		DEBUG(2,("Unable to find domain '%s' in sam\n", domain));
 		return NT_STATUS_NO_SUCH_DOMAIN;
@@ -210,9 +213,13 @@ void cldapd_netlogon_request(struct cldap_socket *cldap,
 					      t->u.simple.value.length);
 		}
 		if (strcasecmp(t->u.simple.attr, "DomainGuid") == 0) {
-			domain_guid = talloc_strndup(tmp_ctx, 
-						     t->u.simple.value.data,
-						     t->u.simple.value.length);
+			NTSTATUS enc_status;
+			struct GUID guid;
+			enc_status = ldap_decode_ndr_GUID(tmp_ctx, 
+							  t->u.simple.value, &guid);
+			if (NT_STATUS_IS_OK(enc_status)) {
+				domain_guid = GUID_string(tmp_ctx, &guid);
+			}
 		}
 		if (strcasecmp(t->u.simple.attr, "DomainSid") == 0) {
 			domain_sid = talloc_strndup(tmp_ctx, 
@@ -234,14 +241,19 @@ void cldapd_netlogon_request(struct cldap_socket *cldap,
 		}
 	}
 
-	if (domain == NULL || host == NULL || version == -1) {
+	if (domain_guid == NULL && domain == NULL) {
+		domain = lp_realm();
+	}
+
+	if (version == -1) {
 		goto failed;
 	}
 
-	DEBUG(0,("cldap netlogon query domain=%s host=%s user=%s version=%d\n",
-		 domain, host, user, version));
+	DEBUG(0,("cldap netlogon query domain=%s host=%s user=%s version=%d guid=%s\n",
+		 domain, host, user, version, domain_guid));
 
-	status = cldapd_netlogon_fill(cldap, tmp_ctx, domain, user, src_address, 
+	status = cldapd_netlogon_fill(cldap, tmp_ctx, domain, domain_guid, 
+				      user, src_address, 
 				      version, &netlogon);
 	if (!NT_STATUS_IS_OK(status)) {
 		goto failed;
diff --git a/source4/lib/ldb/common/ldb_parse.c b/source4/lib/ldb/common/ldb_parse.c
index d9f7dbe524f..5221ef45563 100644
--- a/source4/lib/ldb/common/ldb_parse.c
+++ b/source4/lib/ldb/common/ldb_parse.c
@@ -170,7 +170,7 @@ static struct ldb_parse_tree *ldb_parse_simple(TALLOC_CTX *ctx, const char *s)
 	
 	ret->operation = LDB_OP_SIMPLE;
 	ret->u.simple.attr = l;
-	ret->u.simple.value.data = val;
+	ret->u.simple.value.data = val?val:discard_const_p(char, "");
 	ret->u.simple.value.length = val?strlen(val):0;
 
 	return ret;
diff --git a/source4/libcli/ldap/ldap.c b/source4/libcli/ldap/ldap.c
index cc7f1a10bcc..0c6a466f27c 100644
--- a/source4/libcli/ldap/ldap.c
+++ b/source4/libcli/ldap/ldap.c
@@ -110,7 +110,7 @@ static struct ldap_parse_tree *ldap_parse_filter(TALLOC_CTX *mem_ctx,
    decode a RFC2254 binary string representation of a buffer.
    Used in LDAP filters.
 */
-static struct ldap_val ldap_binary_decode(TALLOC_CTX *mem_ctx, const char *str)
+struct ldap_val ldap_binary_decode(TALLOC_CTX *mem_ctx, const char *str)
 {
 	int i, j;
 	struct ldap_val ret;
diff --git a/source4/libcli/ldap/ldap.h b/source4/libcli/ldap/ldap.h
index 8d4294cf764..54a96d9672a 100644
--- a/source4/libcli/ldap/ldap.h
+++ b/source4/libcli/ldap/ldap.h
@@ -326,6 +326,7 @@ BOOL ldap_parse_basic_url(TALLOC_CTX *mem_ctx, const char *url,
 struct ldap_parse_tree *ldap_parse_filter_string(TALLOC_CTX *mem_ctx,
 						 const char *s);
 const char *ldap_binary_encode(TALLOC_CTX *mem_ctx, DATA_BLOB blob);
+struct ldap_val ldap_binary_decode(TALLOC_CTX *mem_ctx, const char *str);
 
 /* The following definitions come from libcli/ldap/ldap_client.c  */
 
@@ -384,5 +385,6 @@ struct ldap_message *ldap_ldif2msg(TALLOC_CTX *mem_ctx, const char *s);
 const char *ldap_encode_ndr_uint32(TALLOC_CTX *mem_ctx, uint32_t value);
 const char *ldap_encode_ndr_dom_sid(TALLOC_CTX *mem_ctx, struct dom_sid *sid);
 const char *ldap_encode_ndr_GUID(TALLOC_CTX *mem_ctx, struct GUID *guid);
+NTSTATUS ldap_decode_ndr_GUID(TALLOC_CTX *mem_ctx, struct ldap_val val, struct GUID *guid);
 
 #endif
diff --git a/source4/libcli/ldap/ldap_ndr.c b/source4/libcli/ldap/ldap_ndr.c
index 45d9b2729e0..2db85d8f092 100644
--- a/source4/libcli/ldap/ldap_ndr.c
+++ b/source4/libcli/ldap/ldap_ndr.c
@@ -74,3 +74,19 @@ const char *ldap_encode_ndr_GUID(TALLOC_CTX *mem_ctx, struct GUID *guid)
 	data_blob_free(&blob);
 	return ret;
 }
+
+/*
+  decode a NDR GUID from a ldap filter element
+*/
+NTSTATUS ldap_decode_ndr_GUID(TALLOC_CTX *mem_ctx, struct ldap_val val, struct GUID *guid)
+{
+	DATA_BLOB blob;
+	NTSTATUS status;
+
+	blob.data = val.data;
+	blob.length = val.length;
+	status = ndr_pull_struct_blob(&blob, mem_ctx, guid, 
+				      (ndr_pull_flags_fn_t)ndr_pull_GUID);
+	talloc_free(val.data);
+	return status;
+}