On Fri, Mar 21, 2003 at 01:08:15PM +1200, Jim Cheetham wrote:
[snip]

Thanks Jim, better than I would have explained it.

> All this is based on Ethernet - and your DSL line isn't Ethernet. So it 
> is impossible to bridge your LAN (which is Ethernet) with the DSL link.

(Hence why I said that it wasnt a bridge, but a router)

> In order to get traffic from your Ethernet LAN to your DSL 
> circuit-connected network, you need to use a network protocol that 
> isn't wedded to the physical network it runs on. Enter Internet 
> Protocol, IP. IP runs on many different physical networks - especially 
> Ethernet and your DSL link. All of your Ethernet PCs can continue to 
> use Ethernet to talk to each other, but in order to talk to the outside 
> world, they have to use IP. In the local network, all the IP traffic is 
> moved around in Ethernet frames, but that work is now done by low level 
> networking software, and the IP software never knows about it.

Enter the 7-layer OSI model.

http://www.wikipedia.org/wiki/OSI_model
http://www.btinternet.com/~c.j.duley/osi_reference_model.htm
http://www.cs.wmich.edu/~yang/tlt/cs555/
http://www.techexams.net/technotes/ccna/osimodel.shtml

Ad Nauseam...

Mike.
-- 
Mike Beattie <[EMAIL PROTECTED]>                      ZL4TXK, IRLP Node 6184

  If you can stay calm, while all around you is chaos... Then you probably
       haven't completely understood the seriousness of the situation.

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