[Year 12 SofDev] Network Diagrams - Physical or Logical

[Neil Wallace]

You must also be marking SAC 1 now huh??? My comments below refer to the
network diagram as a physical diagram. I use the DFD's and Data Dictionaries
for logical representations in this SAC.

I get similar things Kevin, but I don't have a problem with the serial
representation. In many practical instances that kids are familiar with
firewall features are built into the switch and router. A home ADSL router
that provides firewall, VoIP, wireless and switching (OK maybe hub) services
is an example.

I usually walk the kids through what they may have at home, then tour the
server room and switch cabinets when doing the network structure side of
things. 

So, please all shoot me down if I am out of line here, but as long as the
modem or router, firewall and switch are all in place in the network diagram
(in that order from external to internal) I feel OK with that.

And we haven't got to talking about DeMilitarised Zones for safety in
isolation of onsite servers yet either. . . . 

Enjoy your break.

Neil Wallace
Norwood Secondary College

-----Original Message-----
From: sofdev-bounces at edulists.com.au [mailto:sofdev-bounces at edulists.com.au]
On Behalf Of Kevin Feely
Sent: Friday, 28 March 2008 1:14 PM
To: sofdev at edulists.com.au
Subject: [Year 12 SofDev] Network Diagrams - Physical or Logical

Hi All
Just to clarify one part of these things that i get a number of students
representing firewalls inaccurately.
I find some students like to connect them all up in series (see attached
picture), so that from the switch they go to a firewall, then to a router
then to the phone lines to the internet.
Or even worse the go from the switch to a firewall and then to the internet
with no mention of a router or modem.
I have always put, or seen installed, firewalls (hardware, naturally)
connected  to the network switch (doesn't matter which one) and thats it.
There is no "throughput". ie as you represent a server ,as basically thats
what they are.
The router (or modem if you want to go back a few years) is the throughput
device, on one side the phone line (PSTN, ADSL, CABLE, ETC) and on the other
the network connection to switch via ethernet, to switch from pc via usb
from router, or to switch from pc via serial from modem.
Is this a problem to your students or is it just me?

regards
kevin

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