Remote Listener Cross Registration (across clusters)

Remote Listener Cross Registration (across clusters) can be really confusing to figure out.
Let me explain -

We were to migrate to a new engineered system environment from the old in house 11g cluster.

When the a new DB instance was created on the new hardware, spfile was copied (from the old hardware), but the DBA missed to change the scan listener.

So what happened is that the DB registered itself across.

It's a bit confusing but let me explain.

Hardware1 - Hard1, Scan - SC1
Hardware2 - H2, Scan - SC2

So
- telnet/ping/tnsping all will work fine
and you would get an error like this


SQL> conn sys@MYPRDDB_PR as sysdba
Enter password:
ERROR:
ORA-12545: Connect failed because target host or object does not exist

So if you do a lsnrctl on the Hardware 1, you will find an output similar to below

[grid@Hard1 ~]$ lsnrctl services listener_scan1

LSNRCTL for Linux: Version 11.2.0.4.0 - Production on 07-OCT-2015 06:21:59

Copyright (c) 1991, 2013, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=LISTENER_SCAN1)))
Services Summary...
Service "MYPRDDB_PR" has 2 instance(s).
  Instance "MYPRDDB_1", status READY, has 1 handler(s) for this service...
    Handler(s):
      "DEDICATED" established:159 refused:0 state:ready
         REMOTE SERVER
        (ADDRESS=(PROTOCOL=TCP)(HOST=H1)(PORT=1521))
  Instance "MYPRDDB_1", status READY, has 1 handler(s) for this service...
    Handler(s):
      "DEDICATED" established:3 refused:0 state:ready
         REMOTE SERVER
         (ADDRESS=(PROTOCOL=TCP)(HOST=H2)(PORT=1521))


So, that's the mess, cross registration across cluster. This gave the clue that the remote_listener parameter of the new hardware needs to be changed to the right scan of that hardware.
Once that was fixed, this problem got fixed.


Well you can question me for why this was missed and is really basic, but the idea is for you to get help, in case someone misses a minor configuration.