Device Discovery LMS 3.2

Answered Question
Apr 19th, 2010


pls find the attached,Diagram,

In the attached diagram,would i will be able to discover cisco switch??????

HP switches understand CDP protocol but they dont forward CDP as what i know,correct me if i m wrong.????


I have this problem too.
0 votes
Correct Answer by Joe Clarke about 6 years 6 months ago

See this document which explains Discovery in great detail:

I was referring to making subnets of class C or smaller size to limit the number of nodes pinged.  That is described in more detail in my document.

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Overall Rating: 5 (1 ratings)
Joe Clarke Mon, 04/19/2010 - 21:40

Can you post a JPEG of this topology?  Based on your description, I do not think you will get what you want.  LWhile LMS will be able to find the HP switches via CDP, it will not be able to poll the CDP information from them, and thus will not discover beyond them unless you add a Cisco seed device beyond the HP switches.

thomasandy32 Mon, 04/19/2010 - 23:12

Hello Clarke,

Attached is the Jpeg, All layer 2 Access switches  trunk links are coming to HP CORE 5406,Some of the access switches trunk links are HP switches and beyond that cisco switch is conected to HP Access switches,Can u guide me how to discover all the cisco devices which are below the HP access switches which are connected to Core HP 5406.


Joe Clarke Mon, 04/19/2010 - 23:59

Based on this, you would need to add the Cisco 3550 and Cisco 2960 as seed devices in Discovery for the CDP module.

thomasandy32 Tue, 04/20/2010 - 00:20

Hello Clarke,

My whole campus is setup in this manner,so from ur mail what i understand is while discovering devices i have to add manually 3550 after sucessful entry of 3550 in DCR , i have to keep 3550 as a seed device and pull the 2960 after than when 2960 comes in DCR i have to keep these 2 switches as a seed device and pull the others.

Thanks for reply

thomasandy32 Tue, 04/20/2010 - 12:56

Hello clarke,

why i shld be dependent on cdp when i can use ping sweep on ip range discovery module, when i can ping the whole network.

Pls reply for the above 2 mails ur help will be appreciated.

Joe Clarke Tue, 04/20/2010 - 15:20

There's no reason why you couldn't use Ping Sweep on Range for discovering across your network.  Your initial question was about CDP, so I was answering that.  If you have a mix of Cisco and non-Cisco equipment, and you want to be able to find everything, ping sweep is a good choice.  In fact, what we see today is that most customers are using a mix of CDP and ping sweep.

If you go with ping sweep, try and limit it as much as possible.  That is, keep your subnets small, and reduce the timers as much as possible.  I will be releasing a white paper on Discovery soon, and that will have more complete recommendations.

thomasandy32 Sat, 04/24/2010 - 00:56

Hello Clarke,

As u have mentioned in ur mail to make a subnet small,where is the option to make a small subnet are u r speaking for the filter settings??? i.e include and exclude settings.

i can add manually devices and they are in DCR but when i run ping sweep on IP range module i won't get any output.


thomasandy32 Fri, 04/30/2010 - 14:18

Hello clarke,

Ur document supported a lot,u r a real expert.

Thanks a tonnnnnnnnnns.


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