Perform the following steps to migrate a DB system with IPv4-only network to IPv4/IPv6 dual stack network using Data Guard.

1. Set up a Data Guard association between an existing DB system with IPv4-only network and a new DB system with dual stack network. Initially, the database in the IPv4-only network will be the primary database, and the database in the dual stack network will be the secondary database. For detailed steps, see Enable Oracle Data Guard on a DB System.

2. Perform a database switchover. After the database switchover, the database in the dual stack network will become the primary database. For detailed steps, see Perform Database Switchover and Failover.

   Note:

   Ensure that both databases are synchronized before performing the switchover. The primary and standby databases should be synchronized, meaning there should be no backlog of redo logs on the standby database. You can check synchronization by ensuring that no redo logs are pending to be applied on the standby. Use the DGMGRL> SHOW CONFIGURATION; command to check the synchronization status.
3. Once you are satisfied and sure that the new DB system in the dual stack network is working fine, you can terminate the Data Guard association by deleting the current standby DB system in the IPv4-only network. For detailed steps, see Terminate a Oracle Data Guard Association on a DB System.