Monitoring Linux with dynamic ppp0 DSL Interface

[mlembke]

Hi,

i need to monitor some Linux systems with dynamic ADSL Interfaces.
Everytime the Interface goes down and comes up again, the ifindex changes and the Node has a new Interface ifindex: xxx Name: ppp0.

Is there a way, that this Interface isn't created, just updated?

Thanks,
Markus

---

[victor]

Hi!

Strange that old interfaces remains in interface list. Normally it should be deleted and new interface object with same name but different index created. Can you post output of

nxget -l <server_ip> Net.InterfaceList

before and after PPP session comes down and up again. It should not affect data collection because you can use interface names instead of indexes in all Net.Interface parameters.

Best regards,
Victor

[mlembke]

Hi Viktor,

I'm sorry, but do i run nxget on my Server, proxy?
The Linux system is monitored via snmp and not via NetXMS agent.

Best regards
Markus

[victor]

Hi!

I was under impression that you are using NetXMS agent on server with ppp interfaces. Can you test what interface list returned by SNMP agent using SNMP walk? Like this:

nxsnmpwalk -c community server_address .1.3.6.1.2.1.2.2.1.2

I suppose that it is a bug in Linux snmpd which causes to return all previous instances of ppp interface along with current one.

Another problem is changing interface index. I take a quick look inside ppp module in Linux kernel, and it looks like it assigns new interface index on each ppp connection setup. Because when you collect interface data via SNMP the only option to identify interface is by index, you cannot create simple DCI which will always work, because you'll need to change SNMP OID when interface index changes.

The easiest way to solve this would be to install NetXMS agent on this Linux server - then you'll be able to gather data by interface name. Event if it's some kind of appliance installing NetXMS agent is most likely possible if you can access it's file system and execute commands.

Best regards,
Victor