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Q168036: Link State Routing Basics

Article: Q168036
Product(s): Microsoft Windows NT
Version(s): WinNT:4.0
Operating System(s): 
Keyword(s): kbnetwork
Last Modified: 09-AUG-2001

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The information in this article applies to:

- Microsoft Windows NT Server version 4.0 
- Microsoft Routing and Remote Access Service Update for Windows NT Server version 4.0 
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SUMMARY
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There are 2 types of distributed routing technologies. They are distance vector
and link state. This article discusses link state routing.

MORE INFORMATION
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Routers that use a link state routing protocol maintain a database of their
individual autonomous system (AS)topology. An autonomous system is a group or
collection of networks under common administration using the same routing
protocol, and is sometimes called a routing domain. Autonomous systems are
commonly divided into areas tied together by a backbone area. Each router in an
autonomous system has an identical link state database (LSB). The link state
database is composed of each router's local state.

Routers distribute their local state by flooding the autonomous system with link
state advertisements (sometimes referred to as link state packets). Link state
advertisements (LSAs) are special packets which contain information about
neighbors and route cost. These LSAs can also contain routing information
gathered by other routing protocols and static routes.

All routers in an autonomous system run the same routing algorithm. From the link
state database, each router builds a tree of shortest paths with itself as the
root. The tree contains the route to each destination in the autonomous system.

Common link state routing protocols are open shortest path first (OSPF) and
intermediate system-to-intermediate system interdomain routing protocol (IS-IS).

Additional query words: RRAS
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Keywords          : kbnetwork 
Technology        : kbWinNTsearch kbWinNT400search kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbAudDeveloper kbRRASNTSearch kbRRASNT400
Version           : WinNT:4.0

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