<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"> <HTML> <HEAD> <META NAME="GENERATOR" CONTENT="SGML-Tools 1.0.9"> <TITLE>IP Sub-Networking Mini-Howto: What are subnets?</TITLE> <LINK HREF="IP-Subnetworking-5.html" REL=next> <LINK HREF="IP-Subnetworking-3.html" REL=previous> <LINK HREF="IP-Subnetworking.html#toc4" REL=contents> </HEAD> <BODY> <A HREF="IP-Subnetworking-5.html">Next</A> <A HREF="IP-Subnetworking-3.html">Previous</A> <A HREF="IP-Subnetworking.html#toc4">Contents</A> <HR> <H2><A NAME="s4">4. What are subnets?</A></H2> <P>A subnet is a way of taking a single IP network address and <B>locally</B> splitting it up so that this single network IP address can actually be used on several interconnected local networks. Remember, a single IP network number can only be used on a single network. <P> <P>The important word here is <B>locally</B>: as far as the world outside the machines and physical networks covered by the sub-netted IP network are concerned, nothing whatsoever has changed - it is still just a single IP network. This is important - sub-networking is a <B>local</B> configuration and is invisible to the rest of the world. <P> <HR> <A HREF="IP-Subnetworking-5.html">Next</A> <A HREF="IP-Subnetworking-3.html">Previous</A> <A HREF="IP-Subnetworking.html#toc4">Contents</A> </BODY> </HTML>