This has been a problem since the early days of MRTG which used the same strategy. MRTG did eventually put in an opt-in feature where you can index based upon the ifAlias/ifName. This was particularly handy in the case mentioned where PPP ifIndexes are not stable between reboots or interface flaps. It would also help in the case where Juniper so helpfully re-indexes all your interfaces after a code upgrade. 


The opt-in would ideally be done based upon some (configurable?) match criteria so you can easily have a class of devices adopt this behavior rather than having to touch every single device you want to opt-in. The manual method kind of defeats the automagic nature of Observium. 

From: observium <observium-bounces@observium.org> on behalf of Adam Armstrong via observium <observium@observium.org>
Sent: Tuesday, April 21, 2020 11:30:38 AM
To: 'Observium'
Cc: Adam Armstrong
Subject: Re: [Observium] PPPoE Interfaces Deleted
 

This is just because that’s what’s actually happening. Each new PPP interface is a new interface, with a different ifIndex in SNMP. Observium tracks interfaces by ifIndex, ifAlias/port name is unreliable, a lot of devices don’t provide usable names.

 

This is of course device dependent, but almost everything will work this way.

 

We have thought about having an alternative port rrd handling scheme which names rrds after ifAlias to try to keep data across port changes like this, but it gets really really messy because we’re having to do a lot of blackbox guess work and it’ll rarely operate in a way that doesn’t confuse people and/or cause problem..

 

Adam.

 

From: observium <observium-bounces@observium.org> On Behalf Of Shaun via observium
Sent: 21 April 2020 14:11
To: observium@observium.org
Cc: shaun@sbnetworks.co.za
Subject: [Observium] PPPoE Interfaces Deleted

 

Hi guys,

 

Please if anyone could offer some advice or guidance I would really appreciate it.

 

I recently deployed Observium in my network for monitoring purposes, everything is working great, better than ever expected, except for the following:

 

Each time a PPPoE client interfaces reconnects, the previous data is deleted, interface is deleted and the graphs and usage data start fresh from the time of the new connection.

 

Is there any way of setting up the Observium installation to retain previous session data and usage and just have it “carry on” recording data each time the PPPoE session reconnects?

 

Any assistance will be appreciated.

 

Thanking you in advance

 

Shaun