diff --git a/src/backend/libpq/auth.c b/src/backend/libpq/auth.c
index fe7bc3c9d1d0ecb5921f85b49398897b332a6089..2fd417e6130b33920379ea0ce02def9995d78cbd 100644
--- a/src/backend/libpq/auth.c
+++ b/src/backend/libpq/auth.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/libpq/auth.c,v 1.57 2001/08/15 18:42:14 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/libpq/auth.c,v 1.58 2001/08/16 04:27:18 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -501,13 +501,16 @@ ClientAuthentication(Port *port)
 			status = recv_and_check_password_packet(port);
 			break;
 
-		case uaCrypt:
-			sendAuthRequest(port, AUTH_REQ_CRYPT);
-			status = recv_and_check_password_packet(port);
-			break;
-
 		case uaMD5:
 			sendAuthRequest(port, AUTH_REQ_MD5);
+			if ((status = recv_and_check_password_packet(port)) == STATUS_OK)
+				break;
+			port->auth_method = uaCrypt;
+			/* Try crypt() for old client */
+			/* FALL THROUGH */
+			
+		case uaCrypt:
+			sendAuthRequest(port, AUTH_REQ_CRYPT);
 			status = recv_and_check_password_packet(port);
 			break;
 
diff --git a/src/backend/libpq/hba.c b/src/backend/libpq/hba.c
index d12225ab0eae15ef5e508a1d9c5dcf73fb540b86..f9e7898fb1a59a78fe73dad1b71f8d809be6109b 100644
--- a/src/backend/libpq/hba.c
+++ b/src/backend/libpq/hba.c
@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/libpq/hba.c,v 1.62 2001/08/15 18:42:15 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/libpq/hba.c,v 1.63 2001/08/16 04:27:18 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -227,15 +227,8 @@ parse_hba_auth(List *line, ProtocolVersion proto, UserAuth *userauth_p,
 		else if (strcmp(token, "reject") == 0)
 			*userauth_p = uaReject;
 		else if (strcmp(token, "crypt") == 0)
-		{
-			/* if the client supports it, use MD5 */
-			if (PG_PROTOCOL_MAJOR(proto) > 2 ||
-				(PG_PROTOCOL_MAJOR(proto) == 2 &&
-				 PG_PROTOCOL_MINOR(proto) >= 1))
-				*userauth_p = uaMD5;
-			else
-				*userauth_p = uaCrypt;
-		}
+			/* Try MD5 first; on failure, switch to crypt() */
+			*userauth_p = uaMD5;
 		else
 			*error_p = true;
 		line = lnext(line);
diff --git a/src/include/libpq/pqcomm.h b/src/include/libpq/pqcomm.h
index c709553f69bd6206832b05ed6e2a1118ab383a3a..57a7e79696a4d4c50f43c7cec706ee618f2f6437 100644
--- a/src/include/libpq/pqcomm.h
+++ b/src/include/libpq/pqcomm.h
@@ -9,7 +9,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: pqcomm.h,v 1.56 2001/08/15 18:42:15 momjian Exp $
+ * $Id: pqcomm.h,v 1.57 2001/08/16 04:27:18 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -90,7 +90,7 @@ typedef union SockAddr
 /* The earliest and latest frontend/backend protocol version supported. */
 
 #define PG_PROTOCOL_EARLIEST	PG_PROTOCOL(0,0)
-#define PG_PROTOCOL_LATEST	PG_PROTOCOL(2,1)
+#define PG_PROTOCOL_LATEST	PG_PROTOCOL(2,0)
 
 /*
  * All packets sent to the postmaster start with the length.  This is omitted
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index a681e72beed6ae6e3dcb634a57b21e5192c72e23..bab52c390b394bb2f470d8f44556573b66974465 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -12,7 +12,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: libpq-int.h,v 1.37 2001/08/15 18:42:16 momjian Exp $
+ * $Id: libpq-int.h,v 1.38 2001/08/16 04:27:18 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -45,7 +45,7 @@
  * pqcomm.h describe what the backend knows, not what libpq knows.
  */
 
-#define PG_PROTOCOL_LIBPQ	PG_PROTOCOL(2,1)
+#define PG_PROTOCOL_LIBPQ	PG_PROTOCOL(2,0)
 
 /*
  * POSTGRES backend dependent Constants.