How to Modify SCAN Setting or SCAN Listener Port after Installat

A. To update SCAN setting

1. As per documentation "Oracle Grid Infrastructure Installation Guide", Oracle strongly recommend to configure SCAN name in either DNS or GNS as /etc/hosts file can only resolve to one IP address.

SCAN IP must be in same subnet as public and VIP. If the new SCAN IP will be in different subnet, refer to note 276434.1 to change nodeapps/network resource first.

1a. If you intend to use /etc/hosts for SCAN name resolution, the same and only entry for SCAN name must exist on all nodes.

1b. If you intend to use DNS for SCAN name resolution, remove entries for SCAN name from /etc/hosts on all nodes, and make sure nslookup returns good result on all nodes, for example:

2. Once #1a or #1b is configured properly, execute the following to modify:

If name resolution for SCAN is being switched from local hosts file to DNS, be sure to remove SCAN name in local hosts file on all nodes prior to execute below commands.

2.1. To modify SCAN name or SCAN VIP addresses:

2.1.1. As grid user stop resources:

2.1.2. As root user modify SCAN:

Once SCAN name is changed, update database init.ora/spfile parameter remote_listener to the new one.

2.1.3. As grid user modify and start resources:

2.1.4. To confirm the change

2.2. To change SCAN to be on second network:

By default, SCAN will be configured on first public network (ora.net1.network), however in multiple public network environment, SCAN can run on second or other network.

There's no option to modify SCAN to use non-first network, to change to second or other network, scan_listener and scan resources need to be removed and added back.

In this example, we'll move SCAN from net1 to net2

You can also modify the scan in the second network like below on 12.2

2.2.1. As grid user stop resources and remove scan_listener:

2.2.2. As root user remove and add SCAN:

Once SCAN name is changed, update database init.ora/spfile parameter remote_listener to the new one.

2.2.3. As grid user add scan_listener and start resources:

B. To modify SCAN listener port

As grid user:

1. Modify SCAN listener port:

Update 11gR2 database init.ora parameter: alter system set remote_listener='<SCAN-name>:<new-port-number>' scope=both;



2. Restart SCAN listener so the new port will be effective:

3. Confirm the change: