[mrtg] Able to ping but not snmpwalk

[Steve Shipway]

A 'no such instance' means that you're talking with an SNMP daemon, but it
doesn't have the data you're asking for.

 

This might be for several reasons -

.         Maybe you have your SNMP ACLs configured to deny that OID to the
connecting community?

.         Maybe this OID really does not exist on this device?

.         Maybe you have mis-typed the OID and are not asking for what you
think you are asking for?

 

Of course a ping will work, as that is just and ICMP echo request, and you
know that the host is up (since you're getting a sane response back from the
SNMP daemon).  'ping' checks an ICMP response at the Transport layer.
'snmpwalk' queries the SNMP daemon at Application level.

 

Steve

 

Steve Shipway

 <mailto:s.shipway at auckland.ac.nz> s.shipway at auckland.ac.nz

(GNU Terry Pratchett)

 

From: mrtg [mailto:mrtg-bounces+s.shipway=auckland.ac.nz at lists.oetiker.ch]
On Behalf Of Rick Silacci
Sent: Thursday, 28 May 2015 7:37 a.m.
To: mrtg at lists.oetiker.ch
Subject: [mrtg] Able to ping but not snmpwalk

 

I'm monitoring 5080 devices for latency.  I noticed some of the graphs are
blank.  I did an snmpwalk on the IP's with the blank graphs and I get "No
such instance currently exists at this OID", which would explain the blank
graphs.  The part I can't figure out is that when I ping that same IP I get
a response.

 

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