computer science

Internet Authentication Service

Internet Authentication Service is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Internet Authentication Service rather than just read about it. In short: Internet Authentication Service (IAS) is a component of Windows Server operating systems that provides centralized user authentication, authorization and accounting. Overview While Routing and Remote Access Service (RRAS) security is sufficient for small networks, larger companies often need a dedicated infrastructure for authentication.

Key takeaways

Internet Authentication Service belongs to computer science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Internet Authentication Service to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Internet Authentication Service from memory before moving on to harder problems.

Reference excerpt

Internet Authentication Service (IAS) is a component of Windows Server operating systems that provides centralized user authentication, authorization and accounting.

Overview While Routing and Remote Access Service (RRAS) security is sufficient for small networks, larger companies often need a dedicated infrastructure for authentication. RADIUS is a standard for dedicated authentication servers. Windows 2000 Server and Windows Server 2003 include the Internet Authentication Service (IAS), an implementation of RADIUS server. IAS supports authentication for Windows-based clients, as well as for third-party clients that adhere to the RADIUS standard. IAS stores its authentication information in Active Directory, and can be managed with Remote Access Policies. IAS first showed up for Windows NT 4.0 in the Windows NT 4.0 Option Pack and in Microsoft Commercial Internet System (MCIS) 2.0 and 2.5. While IAS requires the use of an additional server component, it provides a number of advantages over the standard methods of RRAS authentication. These advantages include centralized authentication for users, auditing and accounting features, scalability, and seamless integration with the existing features of RRAS. In Windows Server 2008, Network Policy Server (NPS) replaces the Internet Authentication Service (IAS). NPS performs all of the functions of IAS in Windows Server 2003 for VPN and 802.1X-based wireless and wired connections and performs health evaluation and the granting of either unlimited or limited access for Network Access Protection clients.

Logging By default, IAS logs to local files (%systemroot%\LogFiles\IAS\*) though it can be configured to log to SQL as well (or in place of). When logging to SQL, IAS appears to wrap the data into XML, then calls the stored procedure report_event, passing the XML data as text... the stored procedure can then unwrap the XML and save data as desired by the user.

History The initial version of Internet Authentication Service was included with the Windows NT 4.0 Option Pack. Windows 2000 Server's implementation added support for more intelligent resolution of user names that are part of a Windows Server domain, support for UTF-8 logging, and improved security. It also added support for EAP Authentication for IEEE 802.1x networks. Later on it added PEAP (with service Pack 4). Windows Server 2003's implementation introduces support for logging to a Microsoft SQL Server database, cross-forest authentication (for Active Directory user accounts in other Forests that the IAS server's Forest has a cross-forest trust relationship with, not to be confused with Domain trust which has been a feature in IAS since NT4), support for IEEE 802.1X port-based authentication, and other features. All versions of IAS support multi domain setups. Only Windows Server 2003 supports cross forest. While NT4 version includes a Radius Proxy, Windows 2000 didn't have such a feature. Windows Server 2003 reintroduced the feature and is capable of intelligently proxy, load balance, and tolerate faults from faulty or unreachable back-end servers.

References

External links Deploying Internet Authentication Service (IAS) in Windows 2003 Internet Authentication Service in the Microsoft Windows 2000 Resource Kit Article describing how to log IAS (RADIUS) + DHCP to SQL Deprecated link at archive.today (archived 2012-12-06) Deprecated link at archive.today (archived 2012-12-05) IAS Log parsing utility. Allows to visualize ias log files

Worked examples

Example 1 — a first encounter with Internet Authentication Service

Start with the simplest possible case. Write down what Internet Authentication Service claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Internet Authentication Service before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Internet Authentication Service ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Internet Authentication Service

In research: Internet Authentication Service appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Internet Authentication Service in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Internet Authentication Service is common in secondary-school and first-year university syllabi. It links to neighbouring topics Computer access control, Internet security, Microsoft Windows security technology, so understanding it makes those chapters shorter.
In everyday life: Look for Internet Authentication Service outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Internet Authentication Service in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Internet Authentication Service means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Internet Authentication Service out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Internet Authentication Service in simple terms?

Internet Authentication Service (IAS) is a component of Windows Server operating systems that provides centralized user authentication, authorization and accounting. Overview While Routing and Remote Access Service (RRAS) security is sufficient for small networks, larger companies often need a dedi…

Why does Internet Authentication Service matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Internet Authentication Service?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Internet Authentication Service.