ORA-17628: Oracle error 17629 returned by remote Oracle server

when resync catalog

rman target / catalog rman/@RCAT

RMAN> RESYNC CATALOG FROM DB_UNIQUE_NAME DGs;


RMAN>
user interrupt received
RESYNC CATALOG FROM DB_UNIQUE_NAME DG;

resyncing from database with DB_UNIQUE_NAME DG
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03009: failure of resync from db_unique_name command on default channel at 05/26/2016 16:19:54
ORA-17629: Cannot connect to the remote database server


changed to use password connection

orarac2poc:DGS:/home/oracle/ops/logs> rman target sys/ catalog rman/@RCAT

Recovery Manager: Release 11.2.0.4.0 - Production on Thu May 26 16:20:01 2016

Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.

connected to target database: DG (DBID=1716975309)
connected to recovery catalog database

RMAN> RESYNC CATALOG FROM DB_UNIQUE_NAME DG;

resyncing from database with DB_UNIQUE_NAME DG
starting full resync of recovery catalog
full resync complete

RMAN> RESYNC CATALOG FROM DB_UNIQUE_NAME all;


resyncing from database with DB_UNIQUE_NAME DG
starting full resync o