what about 48 bits?

Joe Greco jgreco at ns.sol.net
Wed Apr 7 06:18:57 CDT 2010


> In article <201004071023.o37ANtww018405 at aurora.sol.net>, Joe Greco 
> <jgreco at ns.sol.net> writes
> 
> >>interoperability and backwards  compatibility were the tipping points.
> >
> >Ah, yes, backwards compatibility: implementing the fantastic feature of
> >breaking the network...
> 
> By "backwards compatibility" I mean the ability to use the new LAN from 
> a laptop that didn't have an Ethernet connection built in, and didn't 
> have an optional [proprietary] internal Ethernet card available either.

There are a lot of things to target with the term, I was picking
conveniently.  :-)

> >we all remember the fun of what happened when
> >someone incorrectly unhooked a 10base2 network segment; D-Link managed
> >to one-up that on the theoretically more-robust 10baseT/UTP by
> >introducing a card that'd break your network when you powered off the
> >attached PC.
> 
> That tale of woe doesn't really sound like it's the fault of backwards 
> compatibility.

No, but I remember network people talking gleefully about the benefits of
10baseT (and come on - it has lots), and how it fixed the "someone needed
to move a PC and disconnected the cables from the T rather than the T
from the NIC" problem...  and along came D-Link (and some other vendors
I think) with the brilliant idea of a host-integrated hub.

Now, remember, some network guys walked around with new-in-bag BNC T's in
their pocket because they'd run across someone who disappeared a T every
month or two, and there's great power in turning your back, twiddling for
a few seconds, and then being able to holler "Network's back up!"...

Unfortunately, power-cycling crashed PC's is (was?) pretty common, and 
many users are (were?) also trained to shut off PC's when done, so here
you've introduced something that is by-design going to fail periodically.
Not just if-and-when someone decides to move a computer and screws it up.
Of course, if someone actually removes the PC in question, and does not
realize that the network actually feeds _through_ the PC, um, well, you
cannot just whip a T out of your pocket to "fix" the network.

To me, this is a Dilbert-class engineering failure.  I would imagine that
if you could implement a hub on the network card, the same chip(s) would
work in an external tin can with a separate power supply.  Designing a 
product that actually exhibits a worse failure mode than 10base2 is ...
strange to me.

I was sarcastically referring to this as "backwards compatibility",
possibly also with New Enhanced Features, ha ha.

> Didn't the operational status of the LAX immigration 
> department fall to zero for almost a whole day, once; as a result of a 
> rogue network card crashing the LAN?

Probably.  Not my area of the country.  There are plenty of examples of
networking disasters.  ;-)

... JG
-- 
Joe Greco - sol.net Network Services - Milwaukee, WI - http://www.sol.net
"We call it the 'one bite at the apple' rule. Give me one chance [and] then I
won't contact you again." - Direct Marketing Ass'n position on e-mail spam(CNN)
With 24 million small businesses in the US alone, that's way too many apples.




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