Bug#647866: Network: Packages over hub via bnc not received

[Ben Hutchings <ben@decadent.org.uk>]

Please reply-to-all, not just to me.

On Tue, Nov 08, 2011 at 08:30:39PM +0100, debian@achwg.dyndns.org wrote:
[...]
> > I would guess that the problem is related to signal levels.  Because you
> > are using hubs, signals have to travel all the way from one computer to
> > the other, whereas a switch or router will receive and re-transmit each
> > packet.  When you remove the coax cable you are shortening the distance
> > between the computers and so the received signal is stronger and there
> > are fewer errors.
> > 
> 
> So this could be tested with a short cable (but >0,5m) between two hubs.
> I will try, but I do not think that this is the problem.

My job revolves around networking hardware and I have seen many
different kinds of networking failures, so please assume that I do
know what I'm talking about.

> > Maybe the original firmware enables higher amplification for received
> > signals, so the network interface can properly decode weak signals.
> > What is the network driver and where is the source for the original
> > firmware?
> 
> 
> 
> Following infos were catched from dockstar device.
> With that version the network works well.
> 
> It seems to be debian also.
>
> Pogoplug:~$ cat /proc/version
> Linux version 2.6.22.18 (bdietrich@brad-ux) (gcc version 4.2.1) #57 Mon Aug 31 16:31:01 PDT 2009
 
This is not a Debian kernel.
 
[...]
> If you need more / other inforamtion please tell tell me.

Just tell me what I asked.  What is the driver (you can probably
find this out with 'ethtool -i eth0') and where is the source code?
Don't tell me kernel.org; I'm quite sure this is modfiied by the
manufacturer and I need to see what they did.

> > 
> > > What I do not understand is that all other linux boxes do not have this
> > > problem.
> > 
> > Because other people do not use 10BASE-2 and hubs!
> 
> That is not be the point. 
> I use this network for years with some linux and windows boxes.
> There must be a difference between Suse and Debian squeeze.
> If I use another linux computer in substitute for the dockstar at the same network point
> the problem does not appear.
 
But then you have changed all the hardware, not just the distribution.
You cannot reasonably infer from that that the important difference is
the change of distribution.

Ben.

-- 
Ben Hutchings
We get into the habit of living before acquiring the habit of thinking.
                                                              - Albert Camus