You plan to install and configure interoperability network services on a Windows 2000 Server so that it can maintain and advertise a list of services that use the NWLink IPX/SPX/NetBIOS Compatible Transport Protocol. Which service should you install?

Introduction / Context:
In mixed network environments where legacy NetWare or IPX/SPX-based services are present, Windows 2000 Server can provide interoperability by using the NWLink IPX/SPX/NetBIOS Compatible Transport Protocol. Many of these environments rely on the Service Advertising Protocol (SAP) to announce and discover network services. This question checks whether you know which Windows 2000 service must be installed to maintain and advertise a list of services using this protocol.

Given Data / Assumptions:

The server runs Windows 2000 Server.
The network includes systems using NWLink IPX/SPX/NetBIOS Compatible Transport Protocol.
You want the Windows 2000 Server to maintain and advertise a list of network services using SAP.
Possible services include Indexing Service, NNTP Service, RIP Listener, and SAP Agent.
The focus is specifically on interoperability with IPX/SPX and service advertisements.

Concept / Approach:
In NetWare and IPX/SPX networks, the Service Advertising Protocol (SAP) is used to announce services, such as file and print services, so that clients can locate them. Windows 2000 can participate in this environment by running the SAP Agent service, which maintains a list of services and advertises them over IPX/SPX. Indexing Service is unrelated to network service advertisement and instead helps search file contents. NNTP Service supports the Network News Transfer Protocol for news servers. RIP Listener can listen for Routing Information Protocol updates but does not manage SAP service advertisements. Therefore, SAP Agent is the correct service for maintaining and advertising the list of IPX/SPX services.

Step-by-Step Solution:
Step 1: Identify that the environment uses NWLink IPX/SPX/NetBIOS and that service advertisement is required. Step 2: Recall that SAP (Service Advertising Protocol) is the mechanism traditionally used to announce services in IPX/SPX networks. Step 3: Recognize that Windows 2000 provides a SAP Agent service that participates in these advertisements. Step 4: Compare this with other services: Indexing Service focuses on file indexing, NNTP Service on news, and RIP Listener on IP routing updates. Step 5: Conclude that SAP Agent is the only service in the list that matches the requirement.

Verification / Alternative check:
If you recall NetWare interoperability scenarios from exam preparation, you will remember that administrators install NWLink IPX/SPX/NetBIOS Compatible Transport and the SAP Agent to allow Windows servers to advertise services in a NetWare style environment. None of the other services play this specific interoperability role, confirming that SAP Agent is correct.

Why Other Options Are Wrong:
Indexing Service – Provides content indexing and search capabilities for files and web content, not network service advertisement.

NNTP Service – Implements the Network News Transfer Protocol for news servers, unrelated to IPX/SPX service advertisements.

RIP Listener – Listens for Routing Information Protocol updates, primarily used for IP routing, not for maintaining a SAP-based list of services.

Common Pitfalls:
The names of Windows services can be confusing, and candidates may mistakenly select RIP Listener because it also sounds like a network service. However, remember that RIP relates to IP routing, whereas SAP is part of the IPX/SPX world. For interoperability questions, pay close attention to which protocol stack is referenced and choose the service that directly interacts with that stack.

Final Answer:
To maintain and advertise a list of services using NWLink IPX/SPX/NetBIOS Compatible Transport Protocol, you should install the SAP Agent service.