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Author Topic: Discovery of IP addresses of connected Nodes  (Read 1447 times)

ageldenberg

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Discovery of IP addresses of connected Nodes
« on: March 07, 2019, 04:42:20 AM »
Hello, NeDi gurus

I have a bunch of Cisco switches where I can see proper MAC addresses of connected nodes but no IP addresses.  Could you point me to the information on how those IP addresses can be discovered.  Do I need to tweak .def files or there are some other tricks.  I read that there is a way to populate MAC addresses from ARP tables via SSH.  How can I incorporate it into NeDi configuration?

Thanks a lot!

SchmuFoo

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Re: Discovery of IP addresses of connected Nodes
« Reply #1 on: March 07, 2019, 11:00:45 AM »
When this is a Layer-3 Switch (Mode) it should work out of the box. Maybe you can post your .def file.

SchmuFoo

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Re: Discovery of IP addresses of connected Nodes
« Reply #2 on: March 07, 2019, 11:15:43 AM »
Example Def File Settings for an Cisco WS-C2960CG-8TC-L working as Layer-3 Switch

SchmuFoo

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Re: Discovery of IP addresses of connected Nodes
« Reply #3 on: March 07, 2019, 11:28:07 AM »
Example Def File Settings for an Cisco WS-C2960CG-8TC-L working as Layer-3 Switch

Oh:

Code: [Select]
ArpND (SNMP) ---------------------------------------------------------------- Thu Mar 7 11:24:11 2019
SNMP:Connect X.X.X.X X v2 Tout:2s MaxMS:1472 Retry:1 NB:0
ERR :ipNetToPhysical The requested table is empty or does not exist

But VS. "Blue Man" Button Result from that same device:

Code: [Select]
ipNetToMediaPhysAddress.X.X.X.X.X: 78:e3:X:X:X:X
[..]

ageldenberg

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Re: Discovery of IP addresses of connected Nodes
« Reply #4 on: March 07, 2019, 03:11:31 PM »
ShmuFoo

I believe you are correct.  The switches where IP addresses are not discovered are Layer2 switches.  Now, what can I do with those?  I do not know the inner working of NeDi.  To my mind it should use the ARP tables from the Layer3 switches and populate Layer2 switches with IP addresses.

I hope someone figured out how to find IP addresses of the devices connected to Layer2 switches.

SchmuFoo

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Re: Discovery of IP addresses of connected Nodes
« Reply #5 on: March 11, 2019, 10:45:17 AM »
As long as you also have an Layer-3 Devices where NeDi can extract the ARP Cache, you should see the Nodes on the Layer-2 Device automaticly.

ageldenberg

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Re: Discovery of IP addresses of connected Nodes
« Reply #6 on: March 11, 2019, 01:45:16 PM »
In some cases the ARP tables are on Palo Alto firewalls.  Does anyone know how to get those into NeDi?  Is there a way to do it via SSH?

Thank you!