How to Modify SCAN Setting or SCAN Listener Port after Installation.
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, This Below steps is for the SCAN IP in same sub-net as public for different sub-net please search for oracle Doc.
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:
Steps to follow:
Precheck
$GRID_HOME/bin$ nslookup New_scan_name.com
Server: xx.xxx.xx.xx
Address: xx.xx.xx.xx#xx
Name: New_scan_name.com
Address: xx.xx.xx.xx1
Name: New_scan_name.com
Address: xx.xx.xx.xx2
Name: New_scan_name.com
Address: xx.xx.xx.xx0
$GRID_HOME/bin$ srvctl config scan
SCAN name: old_scan.com, Network: 1/xx.xx.xx.xx/xxx.xxx.xxx.0/eth0
SCAN VIP name: scan1, IP: old_scan.com/xx.xx.xx.xx2
SCAN VIP name: scan2, IP:old_scan.com/xx.xx.xx.xx0
SCAN VIP name: scan3, IP: old_scan.com/xx.xx.xx.xx1
$GRID_HOME/bin$ srvctl config network
Network exists: 1/xx.xx.xx.xx/xxx.xxx.xxx.x/eth0, type static
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:
$ $GRID_HOME/bin/srvctl stop scan_listener
$ $GRID_HOME/bin/srvctl stop scan
Execution
2.1.2. As root user modify SCAN:
#$GRID_HOME/bin/srvctl modify scan -n New_scan_name.com
Once SCAN name is changed, update database init.ora/spfile parameter remote_listener to the new one.
alter system set remote_listener = "New_scan_name.com:1521" scope=both
2.1.3. As grid user modify and start resources:
$ $GRID_HOME/bin/srvctl modify scan_listener -u
$ $GRID_HOME/bin/srvctl start scan_listener
Post Check:
$ $GRID_HOME/bin$ ./srvctl config scan
SCAN name: New_scan_name.com, Network: 1/xx.xx.xx.xx/xxx.xxx.xxx.0/eth0
SCAN VIP name: scan1, IP: New_scan_name.com/xx.xx.xx.xx1
SCAN VIP name: scan2, IP: New_scan_name.com/xx.xx.xx.xx2
SCAN VIP name: scan3, IP: New_scan_name.comt/xx.xx.xx.xx0
$ $GRID_HOME/bin/srvctl config scan_listener
SCAN Listener LISTENER_SCAN1 exists. Port: TCP:1521
SCAN Listener LISTENER_SCAN2 exists. Port: TCP:1521
SCAN Listener LISTENER_SCAN3 exists. Port: TCP:1521
Ref: ORACLE DOC: (Doc ID 972500.1)
There you good to go.................................................
