Mismatch in port numbering with snmp on GS1920

Millbull

Hi everybody,

I'm monitoring my switches (GS1920-24HP and 48HP) in Observium or in Switchmap but there's a mismatch in the port numbering.

The numbering begins by "0", thus if port #5 is in vlan 200, it's shown that it's port #4 who is is that vlan in observium.

Has anyone experienced this problem ? Any suggestions to fix it ?

Thanks.

Zyxel_Chris

@Millbull,
Could you share your OID number and may I know what is your mib software?

Millbull

Hi Chris, I'm using Observium and Switchmap to monitor my switches.

For the OID, I'm not very sure about what you're asking so I've export this 2 files with a snmp browser. Is that you're asking for ?

Best regards.

Freddy

Zyxel_Chris

@Millbull
Based on the oid you have provided it will polling the object with "ifDescr" which has been defined as display string (4 - octets) 

If you want to polling the interface port number then should use the oid with "ifIndex".

Millbull

Where shall I have to configure this setup ? In the monitoring software ?

Regards.

Zyxel_Chris

@millbull,
I'm not familiar with Observium of Switchmap, but based on the attached you have provided should use the OID/symbolic name witch has end with xxxxx.ifIndex and the type should be integer.

Millbull

Hi Chris,

Observium and Switchmap are 2 different monitoring softwares.

Since the problem appears on these 2 softwares, is there any way to make a change directly into the switches ?

Regards

Millbull

Just to mention, the problem doesn't appear with the Cisco and HP switches, only with the Zyxel.

Zyxel_Chris

Hi @Millbull

Let me explain these 2 OID objects, they are both defined by RFC in RFC1213-MIB.

The definition of ifDescr is "A textual string containing information about the Interface…" It does not stipulate it must use port number. However, ifIndex has defined "A unique value for each interface. Its value ranges between 1 and the value of ifNumber…”, which we have to follow up it.

The different vendor has a different way to handle this, some of them choose ifDescr as their port number and some use ifIndex, hope you can understand.

Millbull

Hi Chris,

Thanks for your answer. I will try to solve my problem with these informations.

Regards.

Freddy