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Re: BGP Problem on 04/16/2007

  • From: Daniele Arena
  • Date: Fri Apr 20 11:04:00 2007
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> I remember this because I had such a reload and it was during a period of heavy cosmic activity.. as the hardware had always been reliable and was reliable after this was beleived to be the cause

We have also started to use this as the standard excuse.
Up to now, people believe us...


Well, there is some documentation on Cisco containing references to
cosmic rays and parity errors:

http://www.cisco.com/en/US/products/hw/routers/ps341/products_tech_note09186a00800942e0.shtml

Cisco 7200 Parity Error Fault Tree

"As with all computer and networking devices, the NPE is susceptible
to the rare occurrence of parity errors in processor memory. Parity
errors may cause the system to reset and can be a transient Single
Event Upset (SEU or soft error) or can occur multiple times (often
referred to as hard errors) due to damaged hardware. SEUs or soft
errors are caused by "noise" most frequently due to high-energy
neutrons generated in the atmosphere by cosmic rays. For more
information on SEUs, refer to the Increasing Network Availability
page.

[...]

Even if systems use Error Code Correction (ECC), it is still possible
to see an occasional parity error when more than a single error has
occurred in the 64 bits of data due to cosmic rays affecting more than
one memory cell, or a hard error in the cache."

Regards,

Daniele.