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Unknown Cisco Device

So, I found something else that was interesting...

The switch: WS-C2960S-24TS-S Version ID V02 does not show up as a switch during the query.

Whereas the WC-C2960S-48TS-S Version ID V03 does show up as a switch during the query.

Also, since we have all the mac addresses for each device, why wouldn't we query the mac address table for the switches and identify where things are plugged into.  This would be do a little better job doing the network layout.

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mrn Cisco Employee
Cisco Employee

Unknown Cisco Device

Hi Chris,

We are currently working on fleshing out our 2960 support, it should hit the production sites with our 7.1 release. So you can expect new functionality, bug fixes, and improved support for these devices.

When investigating discovery oddities, the starting point is the method element of the device. If you look at the device dialog, and go to the info tab, you'll see that every device has a list of one or more discovery types listed there.

In general, we can only identify a specific driver for an IOS device in one of two ways: CDP discovery, or a user-designated driver.

In the case of your WS-C2960S-24TS-S V02, take a look at the method and see if CDP is listed there. If it is not, this would explain why it is not classified as a switch - we don't know enough abut the device.

If the device has CDP enabled, but it doesn't have CDP listed in the method element, it means that whatever device it is connected to is unable to report on its CDP neighbors. This could be for several reasons:

1) The connected device doesn't have the correct credentials entered.

2) The connected device doesn't have OnPlus driver support.

3) The connected device doesn't support CDP, but doesn't pass through CDP packets.

Let me know if any of this helps illuminate your situation.

- Mark

mrn Cisco Employee
Cisco Employee

Unknown Cisco Device

>Also, since we have all the mac addresses for each device, why wouldn't

>we query the mac address table for the switches and identify where things are plugged into.

We do query the MAC address table on most switches. You can see this in the method element of attached devices as CAM discovery. If you don't see CAM listed in discovered devices, you need to check that the switch has a proper device driver and that it has working credentials.

The MAC address table is not a perfect guide to topology, as it only tells us that packets from that device have entered via a specific port. That means the device could be directly attached, or it could be attached via an intermediary device.

Our topology view doesn't really try to get into individual port connections, so I don't know how much help it could get from that information. In general, presence in the MAC address table is helpful, but not a panacea.

I don't have a hand in the code that tries to make a useful topology out of discovery information, so any comments I make in this area are suspect. But it is a fairly difficult problem. What users want to see in the topology view is a diagram that shows how all the devices are physically connected in their network - in other words, a wiring chart.

The information that we collect during the inventory task does not provide us with a wiring chart. We get a network connectivity graph, and that graph may only be loosely mapped onto the physical wiring diagram. So creating a good topology view usually involves at least some guesswork. Getting it right in many cases may require user input to tweak the graph.

That said, we will always benefit from specific problems that our users see.

- Mark

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