RMAN-06820 ORA-17629 During Backup at Standby Site

When a backup is made of the Physcial Standby database, the follwing error is generated:

RMAN-06820: WARNING: failed to archive current log at primary database
ORACLE error from target database:
ORA-17629: Cannot connect to the remote database server

ORA-17629: Cannot connect to the remote database server

But the rest of the backup actually completes successfully:

This is a change of behaviour from onward, so also in 12.x

Per 'unpublished' Bug 8740124, as of, we now include the current standby redo log as part of an RMAN archivelog backup at the standby site. This is achieved by forcing a log switch at the primary site.
However, the connection to the primary fails when attempting to do so.


Do not use operating system authentication to login with RMAN. Use a username and password.

That is, do not use just the "/" (operating system authentication) connect to the standby database:

$ rman target /

Connecting as 'rman target /' 

# it gets the sys user but not the password and so, it does NOT mean it is being explicitly 
# specified to connect as sysdba.

Instead put in the username and password for the SYSDBA user:

$ rman target sys/password@stby

Note from Bug: 17580082

As for having ability to connect from standby to primary, there are few options 

– (Option 1) is to connect as SYSDBA, like: 'rman target sysdba_user/password@stby'. The unaccceptable convenience is that the password is visible in the backup scripts.
 (Option 2) is to setup wallets in order to allow the scripts to connect without having to have a visible password (the password is stored in the wallet)

 Currently only SYS  is allowed to connect for switch or resync operation.

Since putting the SYS password is not done in scripts I systematically opt for the use of a wallet.