Hello.

I am trying to access the interfaces (port states: ifOperStatus) of SCALANCE XR324-12M fw 4.0.4 with SNMP.

Manuals on the topic:

SNMP OPC Profile SCALANCE X-300

Industrial Ethernet Switches SCALANCE X-300 / X-400

MIB II

These manuals suggest I need to use the following address for accessing ports ifOperStatus property for XR324-12M:

Port 1.1: 1.3.6.1.2.1.2.2.1.8.51380225
Port 1.2: 1.3.6.1.2.1.2.2.1.8.51380226
Port 2.1: 1.3.6.1.2.1.2.2.1.8.51380227
Port 2.2: 1.3.6.1.2.1.2.2.1.8.51380228
...
Port 12.2: 1.3.6.1.2.1.2.2.1.8.51380248

The problem is when I try to communicate by UDP, I get an error 16#8103 (noSuchName >>>>The MIB object does not exist ->SNMP_OID_NOT_EXIST).

How do I access the port status?

Hello,

The configuration manual for the X300 you refer to is a the version 2012.
Here the version of march 2016
The manual states: Changes made using the CLI or WBM, can be seen over SNMP only on the AG interfaces. So I would try 34603009 instead of 51380225 for port1.1

Anyway, I would recommend the following general approach.
There are free MIB browsers that you can download from the Internet.
These tools will normally already include the public standard MIB II by default.
These tools allow to browse the SNMP tree just like you can browse a folder structure in Windows.
And you can read the different leaves of the tree.
You can also start what is called a "Walk" or a trough the switch, or a "GET Bulk".

This method allows you to find out what is the correct OID for a given topic.
I tell you that, because the interface information is a table, with an index for each interface.
And may be the index has changed.

In the menu "load/save" of the switch, you can download the private MIB of the switch from the switch itself, and import that private in the MIB Browser.
You will see that you can also get more port status information from the private MIB, ring status,
and more ...

I've downloaded MIB Browser as you have suggested.

Searching the switch gave me this result in the attachment.

Both 1.3.6.1.2.1.2.2.1.8.34603011 and 1.3.6.1.2.1.2.2.1.8.51380227 give the desired result.

Problem still continues as trying to connect from the PLC I get an error there is no such OID.

I do not know why this is happening. I am able to get other parameters with the same connection. For example I am able to get the sysName with 1.3.6.1.2.1.1.5.0.

Siemens support suggested to use wireshark and monitor the switch port to see what is happening.

The problem was in the library, which is probided. S7-300 library only support requests from the PLC to the switch with higest number value of 16383.

The request was looking like this, seen from wireshark:

PLC OID Value in DB: 1.3.6.1.2.1.2.2.1.8.51380227

PLC OID Request to the switch: 1.3.6.1.2.1.2.2.1.8.0

And of course switch returns null value to this request.

Solution is to use S7-1500, where this is fixed or as I did, make a Bulk request for 26 values to get all port values.