when the instance is in restricted mode, a database administrator cannot access the instance remotely through an Oracle Net listener, but can only access the instance locally from the machine that the instance is running on.
Lets try! On the server:
SQL> startup restrict
ORACLE instance started.
Total System Global Area 835104768 bytes
Fixed Size 2149000 bytes
Variable Size 595592568 bytes
Database Buffers 230686720 bytes
Redo Buffers 6676480 bytes
On the client, using an admin user:
Enter user-name: admin@tbag
ORA-12526: TNS:listener: all appropriate instances are in restricted mode
What they forget to say here is the fact that this behavior is obtained just with dynamic listener registration. If I’m going to explicitly specify the SID_LIST within my listener.ora file then I can connect remotely without problems.