E. All these are examples of network connectivity configurations. Networking can be as simple as a dumb terminal connected directly to a server via a serial connection. It can also be as complex as an n-tier architecture that involves clients, middleware, the Internet, and database servers.

C. Heterogeneous Services is the correct answer because these services provide cross-platform connectivity to non-Oracle databases. Oracle Advanced Security would not solve this application problem because it addresses security and not accessibility to non-Oracle databases. Oracle Net would be part of the solution, but another Oracle Network component is necessary. Connection Manager would also not be able to accommodate this requirement on its own.

C. When you are using the Heterogeneous Services capabilities of Oracle Net, you do have the ability to communicate with non-Oracle data sources.

D. The best solution to the problem is the Oracle Internet Directory because it facilitates centralized naming. Advanced Security, Heterogeneous Services, and Oracle Shared Server would not provide a solution to this business need because none of these address the issue of centrally managing network services.

A. The listener is the process that manages incoming connection requests. The listener.ora file is used to configure the listener and must be configured to start a non-default listener. The sqlnet.ora file is an optional client- and server-side file. The tnsnames.ora file is used for doing local naming resolution. There is no such file as lsnrctl.ora.

B. Because the default listener name is LISTENER, simply enter lsnrctl start. The name LISTENER is assumed to be the listener to start in this case.

D. When a user makes a connection request, the listener passes control to some server process or dispatcher. Once the user is attached to this process, all negotiations and interaction with the database pass through this process. If the user supplies an invalid user ID or password, the process waits for a period of time for a valid response. If the user does not contact the server process with a valid response in the allotted time, the server process terminates, and the user must contact the listener so that the listener can again spawn a process or redirect the client to an existing dispatcher. This period of time that the process waits is specified by the connect_timeout_ listener_name parameter. This parameter is specified in seconds.

C. When services are dynamically registered with the listener, their information is not present in the listener.ora file.

C. Although you can use choice A to stop and start the listener, doing so temporarily disrupts clients attempting to connect to the database. Choice D is fine if you are starting and stopping the default listener called LISTENER, but we are using a non-default listener. Choice B is not valid because RESTART is not a valid command-line argument for lsnrctl. Therefore, the best method is C, to use the lsnrctl reload listener1 command to load the new set of values in for the listener without disrupting connection service to the databases that the listener is servicing.

C. The default name of the external procedure process is extproc. lsnrctl is a utility used to manage the listener service. External and procext are not valid responses.

A, B, C. Oracle uses service names in networks in much the same way it uses synonyms in the database. Service names provide location transparency and hide the complexity of connect string information. You can configure Oracle Net to connect in several ways, including hostnaming, localnaming, OID, and Oracle Easy Connect Naming. Oracle Global Naming is not a valid Oracle option.

D. Connection Manager is a middleware solution that provides for multiplexing of connections, cross-protocol connectivity, and network access control. All the answers describe Connection Manager.

B. Hostnaming is typically used in small installations that have few Oracle databases. This is an attractive option when you want to minimize client-side configuration. TCP/IP is a requirement when you use hostnaming.

A. Proxy-based firewalls prevent any direct contact between a client outside the corporate firewall and applications inside a corporate firewall. Filter-based firewalls inspect the packet headers but pass the packet on without modification to the destination application. Proxy-based firewalls act more as a relay between external clients and internal applications.

D. A tnsnames.ora file is configured when you want to use localnaming, and it typically exists on the client workstation. It is also used to resolve a service name. The tnsnames.ora file used in localnaming does indeed support the TCP/IP protocol.

D. OID is Oracle's preferred centralized naming service. Oracle Names Server is no longer supported in Oracle 10g.

B, C. Supplying a net service name that is not contained in the tnsnames.ora file can cause this error. Problems with the tnsnames.ora file can cause this error too. Listener problems would not cause this error.

D. The HOST portion specifies the name of the server to contact. CONNECT_DATA specifies the database service to connect to. The PORT portion specifies the location where the listener is listening on the HOST. SERVICE_NAME is the name of the actual database service.

D. Protocols come with tools that allow you to test network connectivity. One such utility for TCP/IP is ping. The user supplies either an IP address or a hostname to the ping utility. It then searches the network for this address. If it finds one, it displays information on data that is sent and received and how quickly it found this address. The other choices are Oracle-supplied utilities.

A. The correct syntax to use with the Oracle Easy Connect Naming method when you are connecting to a non-URL location is as follows: connect username/password@host:port/service_name. If the service name and the host are identical, you do not have to include the service name. If the port is any port other than the default port of 1521, it must be specified. Because we want to connect to a non-default port where the database name and the hostname are the same, the best answer is A.