nanog mailing list archives

Re: Network scan tool/appliance horror stories


From: Ryan Malayter <malayter () gmail com>
Date: Tue, 30 Oct 2012 00:04:21 -0500



On Oct 29, 2012, at 3:55 PM, "Rutis, Cameron" 
 
6) large stacks of 3750s (six or more members) have issues around CPU during certain SNMP commands (I want to say 
some sort of getbulk type of command)

The first four were pretty minor although #3 could generate a lot of calls to the support center.  #5 was a big deal 
due to the nature of the application.  #6 was impactful because we dropped routing neighbors for about 10 seconds but 
this was a couple of years ago so may have been an old IOS bug.

Saw the same. All of our 3750 stacks (which are small) committed suicide during a trial of Foglight. We had discovery 
timings turned way down, but it still caused a reload on a mix of the last supposedly really stable releases of 12.x.

Not confidence inspiring. TAC was useless and suggested a v15 upgrade despite no known fix. The proposed v15 upgrade 
sent our lab boxes into continuous reload unless you broke the stack and manually wiped each switch. Oh, and port 28 
was invisible on each switch after upgrade, and Gi2/0/28 would throw a syntax error. Wait for new releases, lather, 
rinse, repeat.

Total time to resolution in production was several man-weeks on our side, and a few months calendar time, all because 
the discovery scan revealed how great a "software company" Cisco has become.

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