Ralph Johns

iChat Information Pages


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This page contains two pictures and that essentially is it purpose.

The first shows a Modem and then a LAN. This is for Modem that routes.

The first picture, in terms of IP addresses, would apply where a modem that did not route, such as a Cable modem, was used with a Router

The second picture looks at the overlapping subnets and effectively hidden IP addresses when a modem routes and is used with a router when both are doing DHCP. The Picture is a layered .gif that builds slowly to hopefully demonstrate the issue more clearly.

This is not to say that a modem that routes and a router can not be used together but it is about how they are set up to work together.

Pictorial Representation of Home Network

This is about devices that route. Mainly about the pitfalls of adding a DHCP router to a LAN that has a DHCP Modem already.

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The actual pictures that make up this diagram are for you to gain an idea only. Your computers and modem are likely to look different.

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Representation of a Modem and Router Network

Animated .gif Showing problems with overlapping DHCP servers

If it is too fast then Click and Drag it to your Desktop and open in a Graphics applictaion.

modemrouter gif

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© 2005 Ralph Johns Edited 24/9/2005, 5/5/2006, 25/08/2007
Updated September 2006. Moved to Gargoyles and edited Mar 2007
Edited slightly for new Layout 8:47 PM Sunday; September 21, 2008

Information Block

This site is about iChat from Version 1 through to iChat 4.x.x

It has a mixture of basic info and problem solving help.

The setions below will change for Specifics about info on the page on view

If you find these pages helpful please Donate to help keep them up to date

About This Page

Two pics looking at the pitfalls of adding a Second Routing device doing DHCP to a LAN that already has a DHCP server.


Confirmed to work with Win/IE 5.5 and later (should work in 5.0, but not confirmed), Firefox 2, Safari 3, Opera 9, iCab 3.02 and later, Mac/IE 5, Netscape 6 and later

Old browsers (IE version 4 or earlier, Netscape 4 or earlier) should only see a text-based page which, while not the prettiest option, is still entirely usable.