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


Fatal NI connect error 12547, connecting to:
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


$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


Change permissions as below

cd $GRID_HOME/bin
chmod 6751 oracle

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

Restart the DB instance post changes .. DB will come up