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Subnet Masking

Subnet Masking Definition

Subnet Masking Summary

IP Address Definition

IPv6 Subnet Masking

What is subnet masking? What is it for?

One of the most difficult topics to understand about TCP/IP appears to be subnet masking. Many books on TCP/IP ignore it or give it only a paragraph or one page in a 500 page book. The few I've seen that do give subnetting serious attention fail to provide a good basic definition. Without a good definition, the difficulty of the material is magnified. I hope the definition linked above will provide you the insight you might otherwise miss.

The second link above began as an article written to help people prepare for Microsoft's TCP/IP certification exam, but it's been rewritten to generalize it a bit more for anyone who wants to figure out how subnet masking works.

The third link is a definition of IP Addressing, in response to requests from a few folks who were having trouble with that.

The fourth link discusses subnet masking in IPv6.

If you have specific questions you need answered, try the Networking Resource Channel at Experts-Exchange.

Copyright 1999-2006 John Lambert, all rights reserved.
John is a premier field engineer with Microsoft.

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