Error connecting ASM ORA-15055: unable to connect to ASM instance Fatal NI connect error 12547 ORA-12547: TNS:lost contact

TNS-12547: TNS:lost contact
    ns secondary err code: 12560
    nt main err code: 517
ORA-15055: unable to connect to ASM instance
ORA-12547: TNS:lost contact
TNS-12545: Connect failed because target host or object does not exist


Cause:

$GRID_HOME/bin/oracle or $ORACLE_HOME/bin/oracle permission has been changed

ls -al $GRID_HOME/bin/oracle
-rwxr-x--x 1 grid oinstall 200678464 Jun 28 14:54 oracle 

ls -al $ORACLE_HOME/bin/oracle
-rwxr-x--x 1 oracle asmadmin 228886191 Jun 28 15:41 oracle

Solution:

Change permissions as below 

cd $GRID_HOME/bin
chmod 6751 oracle

cd $ORACLE_HOME/bin
chmod 6751 oracle

Once it looks as below the problem is solved...

ls -l $GRID_HOME/bin/oracle
-rwsr-s--x 1 grid oinstall 203974257 Jun 29 09:30 oracle

ls -l $ORACLE_HOME/bin/oracle
-rwsr-s--x 1 oracle oinstall 232399431 Jun 29 13:47 oracle