[c-nsp] Router failure - config lost?

[Garry]

Hi *

I've got something of a question that's not necessarily a clear
technical problem or config problem ... rather just scoping as to
whether other people have come across this, too ...

We have a customer who has some 400+ locations. All of these are
connected to the central office via an MPLS-based network, using aDSL
lines. Every location has an identical 876-W-G-E-k9 router, with (apart
from DSL username and IP address) identical config. This network has now
been in operation for something like 18 months, and is working nicely.

Now, on average 1-2 locations per month go down, losing DSL
connectivity, and even a power-cycle and DSL port reset by the
DSL-provider won't work, at which point we configure a replacement
router and send it out. We usually get the defective router back for
analysis, and apart from a hand full of cases in which the routers where
physically damaged (lightning, spikes on the power supply etc.), most of
the defective routers have simply lost their configuration file. On one
occasion, the whole router flash was cleared, removing the IOS. On yet
another occasion, I think we found the stock config file (the one with
the large header, "cisco" login etc.) on the router (which I thought was
really weird).

In all those cases, we have opted to re-use the router, if for nothing
else than to see whether it was an actual hardware defect ... to date,
no router has shown that behavior twice (we track the ser#).

As for the configs/routers themselves, the locations do not have any
username/pw to log in to the routers. External access shouldn't be
possible, as the network itself has no direct Internet connectivity.

Has anybody else here ever experienced effects like this?

Tnx, -garry