listener.ora and tnsnames.ora?

These are in the location cd $ORACLE_HOME/network/admin

vi listener.ora
prod = ( DESCRIPTION_LIST = ( DESCRIPTION = ( ADDRESS = ( PROTOCOL = TCP )( HOST = 192.168.205.131 )( PORT = 1521 ))))

SID_LIST_prod1 = ( SID_LIST = ( SID_DESC = ( ORACLE_HOME = /u01/app/subbu/product/11.2.0/dbhome_1 )( SID_NAME = prod )))

vi tnsnames.ora


to_subbu1 = (DESCRIPTION = (ADDRESS = (HOST = subbu1.erp.com)(PROTOCOL = TCP)(PORT = 1521))(CONNECT_DATA = (SERVICE_NAME = subbu1)))