Listener

How to Prevent Remote Service Register with Listener

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A vulnerability related to TNS listener has been reported in Oracle Security Alert for CVE-2012-1675, which is disclosed as “TNS Listener Poison Attack”. Attackers may exploit it to manipulate database instances without any authentication. A remote user may exploit it to influence the confidentiality, integrity and availability of database systems. With applying Class of Secure […]
Listener

How to Add Static Service Registered in Listener

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Static Service Registration Dynamic service is a representative which is registered with the listener when the instance is up and running on the server, whereas static service can be used to service external connections with or without a running instance on the server. According to Oracle 18c Advanced Features of Oracle Net Services, the use […]
Listener

How to Add a Cluster Listener on Second Network to Grid

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I assume that you have added the second network to the grid infrastructure. Let’s continue our work. Make sure the second network is available in the grid infrastructure. [grid@primary01 admin]$ srvctl config network -k 2 Network 2 exists Subnet IPv4: 10.0.8.0/255.255.255.0/eth2, static Subnet IPv6: Ping Targets: Network is enabled Network is individually enabled on nodes: […]
Listener

How to Resolve PRCN-2065 PRCN-2067

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For preventing port 1521 from mistakenly being assigned by other listener, the clusterware won’t allow port 1521 to be reassigned, no matter what the network is the default one or not.[grid@primary01 ~]$ srvctl add listener -l listener2 -k 2 -p 1521PRCN-2061 : Failed to add listener ora.LISTENER2.lsnrPRCN-2065 : Ports 1521 are not available on the […]
Listener

How to Resolve Endpoint Listener is Not Listening to Public IP

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I found that I can connect the database via VIP or SCAN, but not Public IP. I checked the endpoint listener. It did not listen the public IP. [grid@primary01 ~]$ cat $ORACLE_HOME/network/admin/endpoints_listener.ora #Backup file is  /u01/app/12.1.0/grid/network/admin/endpoints_listener.ora.bak.primary01 line added by Agent LISTENER_PRIMARY01=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=primary01-vip)(PORT=1521))(ADDRESS=(PROTOCOL=TCP)(HOST=127.0.0.1)(PORT=1521)(IP=FIRST))))         # line added by Agent It was listening 127.0.0.1, no […]
Listener

When Listener Seems Not Working in RAC

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You may found out the listener seems not working:[oracle@primary01 ~]$ lsnrctl statusLSNRCTL for Linux: Version 12.1.0.2.0 – Production on 05-JUN-2016 19:40:08Copyright (c) 1991, 2014, Oracle.  All rights reserved.Connecting to (ADDRESS=(PROTOCOL=tcp)(HOST=)(PORT=1521))TNS-12541: TNS:no listener TNS-12560: TNS:protocol adapter error  TNS-00511: No listener   Linux Error: 111: Connection refusedBut the incoming connections are all established and listener seems pretty healthy from […]
Listener

TNSPING Errors Collections

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tnsping tnsping is a utility provided by Oracle to test the listener is available or not from clients. If there’s any problem in the path to the destination, it will fail with different aspects. Here I list several possible error types below for your reference. “tnsping is not recognized as an internal or external command” […]