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Re: [LUG] OT: Fwd: Net approaches addressing limit

 

On Wed, 12 May 2010, Grant Sewell wrote:

On Wed, May 12, 2010 at 8:57 AM, Gordon Henderson
<gordon+dcglug@xxxxxxxxxx> wrote:
On Wed, 12 May 2010, James Fidell wrote:

At least 15 years...

I was working for an ISP in 1995 when the great debate was kicking off and
CIDR was "invented" Lots of routers back then (ie. cisco) were buggy as they
had all the netmasks for the old "Class A,B,C" networks hard-wired into
them. We were using BSD boxes as routers back then, so didn't really have
any issues with the "experimental" /16's RIPE gave us (out of Class A space)
to .. er .. experiment with. (And people today still talk about Class A, B,
.. networks )-:

Perhaps CIDR should be covered sooner but it still useful for students
to learn about it in stages - start with classful and get 'em to setup
a 2-router configuration with Class A on the LAN side of Router A,
Class B between the 2 routers (ie pretend WAN side) and Class C on the
LAN side of Router B - they can then easily see the differences
between the 3 sections and should be able to visualise the process of
data flowing from Router-A-LAN to Router-B-LAN via the pretend WAN.

I disagree. In these enlightened days, classed addressing is dead and should not be mentioned at all other than in history lessons.

No-one uses classed addressing in todays real-life Internet. Networks are just that - a network base and a subnet mask, or a /prefix. Nothing more, nothing less. Anyone coming to me looking for a job and asking about what Class C networks I have would be shown the door.

Stop teaching classed network addressing. They went out of fashion 15 years ago.

Gordon

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