A power cycle and a reboot should be identical in almost every case.  The
reboot actually triggers a hardware reset internally in the processor,
which should clear everything out.  Of course as soon as I say that it is
identical, someone will find an example where it is not.

I'm not where I can look at the trace you sent, but I'm surprised it
contains errors.  I do know that the unit will return a response which may
look like this if the oid is invalid.

Did you adjust your oids in cacti after the removal of the mystery
expansion unit from the table?  If not, this is likely the problem.

In regards to the unit being there grin the factory..  My guess is if you
had this unit listed in there from the get go, then it probably was the
expansion unit we use to test the expansion bus here.  It's supposed to be
factory reset before shipping but it would not shock me if it wasn't.   We
actually had a short period that a largish percentage went out not factory
reset due to a tester software issue.   Not really a problem but we hate to
have them go out in any other state.
On Oct 24, 2014 5:08 PM, "Bill Prince via Af" <af@afmug.com> wrote:

>  You mean from the web GUI?� Sure.
>
> I presume a power cycle does something different from a reboot?
>
> I was always curious about this particular SiteMonitor, as it came up with
> the extra device on the expansion bus from the get-go.� I'd never worried
> about it, and then I saw the discussion about getting rid of old devices
> with the zeroed-serial trick.
>
> Don't go there!� It's a trap!
>
> bp
>
> On 10/24/2014 2:52 PM, George Skorup (Cyber Broadcasting) via Af wrote:
>
> Can you post a screenshot of your expansion, binary and analog tabs?
>
> Also, I bet if you power-cycle it, it will be fine again. I was working
> with Forrest on a bug where the SyncInjector and some other newer modules
> would mysteriously disappear from the bus. He was able to reproduce and get
> a fixed up firmware load for the modules. Something about one thing booting
> up faster than another, or something like that.
>
> On 10/24/2014 4:41 PM, Bill Prince via Af wrote:
>
> Gotcha!
>
> I removed all the Data Sources except one (PWR1).� Suddenly that data
> was making it into cacti.
>
> Then I added back in all the Data Sources coming _JUST_ from the
> SiteMonitor itself.� That also worked.
>
> Then I added in one of the Data Sources from the SyncInjector (sync
> events), which happens to be the only unit on the expansion bus past where
> I removed the non-existent unit.� This broke it again.
>
> So I have apparently uncovered a bug where removing a unit from the
> expansion bus (by zeroing the serial number) that causes the SiteMonitor to
> break SNMP responses.� I think it's probably just a bad checksum, but I
> will leave that up to him.� I forwarded the pcap trace to him.
>
> I will probably also swap out the SiteMonitor that has the problem.
>
> Thanks guys!
>
> bp
>
> On 10/24/2014 1:57 PM, Bill Prince via Af wrote:
>
> Then again....
>
> Not sure why I didn't notice this the first (or second) time.� Wireshark
> is telling me I have a malformed packet; either a broken header or bad
> checksum.� So even though the SNMP response is coming in with the
> expected data, it's getting dropped before is gets into cacti because of
> the malformed packet.
>
> This would explain why removing a unit on the expansion bus changed
> things...
>
> bp
>
>
>
>
> On 10/24/2014 1:32 PM, Bill Prince via Af wrote:
>
> OK. Confirmed.� The SiteMonitor is getting the SNMP requests, and it is
> responding with the expected values.
>
> I ran a pcap trace both at the SiteMonitor as well as at the ethernet port
> on the cacti server.� SNMP requests/responses are going both ways (and at
> both ends). In fact, spine appears to be doing 3 retries.
>
> One thing I didn't expect is that just before the SNMP requests, there are
> two attempts to open a telnet on the SiteMonitor.� Not sure where that is
> coming from, except perhaps for the Manage plugin (which I de-installed
> several weeks ago).
>
> So something is broken inside cacti.� How/why this was caused by zeroing
> a serial number from a non-existent expansion unit is completely baffling
> to me.
>
> I also have no clue how to fix it, because cacti "thinks" there was no
> response.
>
> bp
>
> On 10/24/2014 11:16 AM, George Skorup (Cyber Broadcasting) via Af wrote:
>
> I am thoroughly confused. Is your community string correct? Can you
> increase the device SNMP timeout, like 1000ms instead of 250ms. What's your
> device down detection set to? Is it showing down in the device list?
>
> I have seen some base units go kinda screwy and respond slower and a
> reboot doesn't fix it, they needed a power-cycle.
>
> On 10/24/2014 11:25 AM, Bill Prince via Af wrote:
>
> Now thrice.
>
> No joy in Mudville.
>
> bp
>
> On 10/24/2014 8:07 AM, Bill Prince via Af wrote:
>
> Yah.� Twice now.
>
> bp
>
> On 10/23/2014 11:06 PM, George Skorup (Cyber Broadcasting) via Af wrote:
>
> Gotta be the poller cache. Did you try a rebuild?
>
> On 10/23/2014 11:03 PM, Bill Prince via Af wrote:
>
> Getting closer.� When I look in the SNMP cache, there is no entry for
> the device.
>
> Looking in the log (without debug), I get:
>
> 10/23/2014 08:34:25 PM - SPINE: Poller[0] Host[797
> <http://10.13.112.20/host.php?action=edit&id=797>] TH[1] DS[12316
> <http://10.13.112.20/data_sources.php?action=ds_edit&id=12316>] WARNING:
> SNMP timeout detected [250 ms], ignoring host '10.13.114.254'
>
> So there is something causing the SNMP request to barf inside cacti.�
> When I do an snmpget from the CLI, it all looks fine.� Likewise, the
> realtime plugin is working fine too.
>
> So when realtime is doing the SNMP queries outside the poller, they are
> fine.� Just when spine is doing the SNMP requests.
>
>
> bp
>
> On 10/23/2014 4:12 PM, George Skorup (Cyber Broadcasting) via Af wrote:
>
> You divided by zero, didn't you?
>
> Are you sure your modules are in the same order as before?
>
> On 10/23/2014 1:29 PM, Bill Prince via Af wrote:
>
>
> I noticed an "Expansion Unit" on one of my SiteMonitors this morning.�
> It said something about "Device Removed" or something like that.
>
> Remembering the discussion the other day on this topic, I put a "0" in the
> Serial # for the non-existent unit, rescanned, & rebooted.
>
> Now, none of the OIDs work in Cacti.� If I do a simple snmpget on any of
> the OIDs that I use, the correct information comes back. Several of the
> OIDs are on the base unit anyway, so they would not have moved, and
> further, the OIDs don't reference the serial number.
>
> So... what did I do, and how do I fix it?
>
>
>
>
>
>
>
>
>
>
>
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>

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