06-17-2022 02:33 AM
Hello. We have an estate of C9200 switches. They are all running the same IOS version 17.03.04b. Strangely, the interface OIDs for some of them are offset, see example below (Vlan 1 for one of them is in the middle, for the other at the end).
This is wreaking havoc with our NMS
Is this normal, or is it a bug? Is there any way via configuration to freeze the OIDs across the estate?
06-17-2022 02:40 AM
- From a Cisco viewpoint it is probably not too important and may for instance relate to a vlan(s)(1) being effectively defined and configured/used (or not).
M.
06-17-2022 02:43 AM
Aren't the OIDs defined at first boot? If so, shouldn't this be independent of the configuration?
06-17-2022 02:55 AM
- I don't think so , because vlan-interfaces can be added and configured after boot (too). Albeit unrelated to initial post , note also that OID's are for instance generated on devices where line cards can be added or removed , then OID's become kind of 'dynamic'.
M.
06-17-2022 03:13 AM
I verified that "interface vlan 1" is created and "shutdown" on all the switches consistently. Also, these are fixed config switches with no support for linecards and modules, so all this is very strange.
06-17-2022 03:27 AM
OID is standard, its based in the information available SNMP walk will get it, check the one showing VLAN 1 ( show run config, also show ip interface briend, show interface status - get is that information showing correct just to validate ?)
06-17-2022 03:43 AM
Just verified "show vlan", "show ip int brief", they are exactly the same for both switches. What I will do is remove "vlan 1" from the database and also "interface vlan 1" as we don't use this Vlan.
06-17-2022 04:36 AM
I have a feeling this has something to do with the way the switches were initially stacked. In one case, Vlan 1 appears before the second stack, in the other case Vlan 1 appears after the second stack. Looks like something to do with the sequence.
06-19-2022 03:05 AM
I found the answer.
I tested this multiple times and found consistent behaviour. So basically, to get consistently OIDs, all switches in the estate need to follow the exact sequence of first boot+connecting stack cables
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