[PLUG] Puzzling networking problem

[mjd-lists-plug@plover.com (Mark Dominus)]

I have a recurring network problem.  Packets addressed to one or
another of my static addresses will just stop arriving.

I believe the problem isn't on my side.  This is because I can run ping
on a remote network, sending packets to one of my working addresses,
and the effect is obvious: the 'activity' lamp on my DSL modem blinks
every second, whenever the ping packets come in.   The periodic
blinking starts when I run the ping and stops when I stop the ping, so
it's clear that the ping packets are arriving at the modem.

When I run the same 'ping' command to send packets to a non-working
address, the lamp does not blink in this was.  I think this shows that
the packets are not making it to my DSL modem at all.  I think that
this rules out anmy configuration problem on my local network or my
hosts.

I have had a problem with each of my three static addresses in turn.
First there was a problem with 216.158.52.121.  Packets sent to that
address were not arriving, and packets to the other two addresses were
arriving just fine.  I talked to my provider, DCANet, on the phone,
and the problem magically vanished while I was on the phone with them.
I said "Whatever you did must have worked."  They told me they had
done nothing.  I certainly had also done nothing, since I was waiting
on the phone.

A week later I left for Ireland, and a week after that packets stopped
ariving at 216.158.52.122.  I sent DCANet email about it, but the
problem was not resolved for eleven days.  Once again, I know that I
did nothing to change my local network either to cause the problem or
to fix it.  I was in Ireland when it happened.  Once again, DCANet
disclaims responsibility.

This morning just past midnight, the same problem occurred with my
216.158.52.119 address.  This was after I had gone to bed.  Once again
the ping tests, which I ran in the morning, showed that the packets
were not arriving on my local network at all.  After about twelve
hours, the problem went away again.

DCANet has not been helpful.  The technical support manager I have
been working with, David Roehsler, does not seem to have a good
understanding of how to solve problems.  His response was to check the
static configuration at DCANet and report that everything was fine.
He wanted me to try pointless diagnostics like rebooting my host.
Since I can observe anomalous behavior when the host is not even
plugged into the network, this is obviously not going to help.
Roehsler likes to check the static configuration.  He checked it twice
more and found that it was the same all three times.  It's hard not to
be make a sarcastic remark about this.  I suggested that someone get
on the phone with me and try sending some packets through the network
to see how far they actualy got, and he did not respond to that
suggestion.  Apparently if the static configuration looks OK, there is
not any problem.

I am really mystified here, and it seems that DCANet and I are getting
into a noncommunicative mode.  They will not answer my questions and
they take a long time to return my calls.  I'm afraid that they have
tagged me as a troublesome customer.  From my end, it looks like there
is a problem in the network that is not my fault and they won't help
me track it down.

Has anyone had any similar sort of technical problem?  Does anyone
have any advice for dealing with a service provider that seems to
think that I am the problem here, and that the only way to deal with
me is to ignore me?

I'd be grateful for anything constructive.


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