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

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

This Blog is intended to resolve below errors observed in DB alert log file due connectivity issue between DB Instance & ASM disk/Instance

Errors:

Fatal NI connect error 12547, connecting to:
 (DESCRIPTION=(ADDRESS=(PROTOCOL=beq)(PROGRAM=/u01/app/grid/product/11.2.0/grid/bin/oracle)(ARGV0=oracle+ASM_asmb_remdev)(ENVS='ORACLE_HOME=/u01/app/grid/product/11.2.0/grid,ORACLE_SID=+ASM')(ARGS='(DESCRIPTION=(LOCAL=YES)(ADDRESS=(PROTOCOL=beq)))'))(enable=setuser)(CONNECT_DATA=(CID=(PROGRAM=oracle)(HOST=remedy-ebu-dev-db1)(USER=ora11g))))
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
ERROR: Failed to connect with connect string: (DESCRIPTION=(ADDRESS=(PROTOCOL=beq)(PROGRAM=stance
ORA-12547: TNS:lost contact
,ORACLE_SID=055: unable to connect to ASM instance

Cause:

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

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

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

Solution:

Change permissions as below

cd $GRID_HOME/bin
chmod 6751 oracle

cd $ORACLE_HOME/bin
chmod 6751 oracle

it should look like having sticky bit ..

ls -l $GRID_HOME/bin/oracle
-rwsr-s--x 1 grid oinstall 203974257 May 11 09:30 oracle

ls -l $ORACLE_HOME/bin/oracle
-rwsr-s--x 1 oracle oinstall 232399431 May 14 13:47 oracle

or 

ls -l $GRID_HOME/bin/oracle*

-rwxr-x--- 1 oracle oinstall         0 Sep  5  2010 oracleO*

-rwsr-s--x 1 oracle asmadmin 228886468 Jan 11  2012 oracle*

ls -l $ORACLE_HOME/bin/oracle*

-rwxr-x--- 1 oracle oinstall         0 Sep  5  2010 oracleO*

-rwsr-s--x 1 oracle asmadmin 228886468 Jan 11  2012 oracle*

Restart the ASM and DB instance after changing permission  .. DB will come up