Multiple databases (that are not replicas) cannot share wallets, because wallets contain a database's identity. Therefore, if a sqlnet.ora file contains a wallet location, then multiple databases cannot share that sqlnet.ora file.
In order to share a single sqlnet.ora file among multiple databases, the following preconditions are required:
User authentication should use passwords or Kerberos.
The wallet containing the password should reside at the default wallet location, which is where Database Configuration Assistant creates it.
If the preceding conditions are met, then multiple databases can share the sqlnet.ora file because no wallet location information is stored in that file.
However, when SSL authentication is used between the user (client) and the database, the wallet location must be specified in the database server's sqlnet.ora file. Such a sqlnet.ora file cannot be shared by multiple databases for SSL-authenticated enterprise users.