[Ti] Ethernet Connection Problem

[Amara Lynn Graps]

On Thursday 16 June 2005 01:36, Kynan Shook wrote:

I/we (sys admin people) solved the problem, although
at the end we are not sure what was the problem. More
below.

> Well, the first thing you should do, of course, is to check your  
> cable and other connections. 

Yes, we checked, swapping cables too.

> Next thing to check is the Network preference pane - 

The IP numbers (address, router, dns server) was fine, 
but the subnet mask was not what I thought it should 
be (.254 instead of .255), but then I wonder why it has
worked for the last 2.5 years..

> One thing I used to see occasionally when I worked at an Apple  
> Authorized Service Provider is that the contacts inside a well-used  
> Ethernet port can get bent too far down.  If you look directly 
>inside  the port, you will see a row of 8 contacts sticking up.  
>Ideally, all 8 should be sticking up the same height.  If they're 
>not, it's possible that a few of them were bent by while inserting 
>and removing plugs, something that can happen after a few years. 

This could have been part of the problem. The Ethernet cable
going into my laptop is not high quality (to say the least).
I was fiddling with the port alot by the end of the evening.

The problem, as near as I can tell, was that somehow a mismatch
occured between the Ethernet address on my computer and what the
network people were using for the Ethernet address
attached to my IP node. 

You see the network here is not only firewalled, each IP
is fixed to one computer that the LAN recognizes in its 
database. The reason for this was that in the past some
pranksters(?) were spamming from within the LAN (and our 
network was getting break-ins from without at the same time),
therefore one cannot, say, plug in different computers to connect 
another computer to a specific IP address, only one computer
is allowed. Initially though, the LAN software must 'open' up the 
Port, and grab the Ethernet address from the computer (or an 
operator can type it into the database), then it 'locks' the 
port/IP to that computer.

So then through the process of 'opening' and 'closing'
the port a few times, something got set in the proper way.
And that is as far as I know what caused that problem. 
A big relief, for me, that it was not hardware. I'm 
so dependent on this laptop.. 

Thanks for the good advice and suggestions!

Amara

-- 

*********************************************************************
Amara Graps, PhD        www.amara.com
Istituto di Fisica dello Spazio Interplanetario, CNR - ARTOV, 
Via del Fosso del Cavaliere, 100, I-00133 Roma, ITALIA
tel: +39-06-4993-4375      fax:  +39-06-4993-4383
Amara.Graps at ifsi.rm.cnr.it http://www.mpi-hd.mpg.de/dustgroup/~graps/ 
**********************************************************************
"We came whirling out of Nothingness scattering stars like dust." 
--Rumi