[Discuss] Networking oddity

[Alan W. Irwin]

On 2015-08-23 22:18-0000 Deryk Barker (Honorary Colleague) wrote:

> I think I must be losing my marbles....
>
> Just installed Mint 17.2 for the fourth time in a week - this is on 4 separate machines.
>
> Now for the strangeness: the latest install is on my main server, which serves music, video and print services.
>
> Even with the firewall disabled I cannot connect to this machine - ssh, vnc, nfs - at all, I simply get connections refused.
>
> As I say the firewall is disabled (the whole network is behind a firewall anyway) and I have all the relevant software (openssh-server tightvncserver nfs-kernel-server) installed.
>
> I put this on my main desktop machine and my wife's desktop and my laptop and had no such problems. I can't even see anything in the log files.
>
> And now for the latest piece of strangeness: I CAN print from another machine...
>
> If anyone has any thought, please let's have them.

Hi Deryk:

Can you summarize the situation as you are getting good networking on
3 machines but the 4th is failing to network with all 4 machines
having the same distribution and _identical_ networking setup?

If, for example, your networking setup is not absolutely identical on
the one bad machine because it is a server, then I would try temporarily to
make that networking configuration absolutely identical to the others
to see if that matters.

If there is an absolutely identical networking configuration, then
could your networking chip/card on that bad machine just be (1)
accidentally disconnected, (2) bad, or (3) just not properly supported
any more by the Linux mint kernel?  Tracing all physical connections
might find something in the first case, and in all cases, you might
want to try swapping in a different networking card (say from one of
the working machines if those still have network cards) to see if that
matters.

I hope this discussion of some obvious possibilities might help
you to find out what the real issue is if only by process of
elimination.

Anyhow, it is an interesting problem you have described, and I hope
you will be able to figure it out quickly.

Alan
__________________________
Alan W. Irwin

Astronomical research affiliation with Department of Physics and Astronomy,
University of Victoria (astrowww.phys.uvic.ca).

Programming affiliations with the FreeEOS equation-of-state
implementation for stellar interiors (freeeos.sf.net); the Time
Ephemerides project (timeephem.sf.net); PLplot scientific plotting
software package (plplot.sf.net); the libLASi project
(unifont.org/lasi); the Loads of Linux Links project (loll.sf.net);
and the Linux Brochure Project (lbproject.sf.net).
__________________________

Linux-powered Science
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