Re: DDMi - Discover DHCP Clients w/o DHCP Server Discovery (201 Views)
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Contributor
mapu39
Posts: 14
Registered: ‎05-08-2007
Message 1 of 4 (201 Views)

DDMi - Discover DHCP Clients w/o DHCP Server Discovery

Hi all,

one of our customers wants to discover and manage DHCP clients. The security processes actually do not allow to activate any sort of snmp (v1/2/3) needed for dhcp discovery (read arp cache).

So is it possible to discover and manage dhcp clients without activating dhcp discovery ?

Are there any great cons? What are your experiences ?

For information: dhcp lease is set to about 7 days.

Thank you for your help !

Best regards,
Matthias
Honored Contributor
Jeff Sikorski
Posts: 655
Registered: ‎07-09-2009
Message 2 of 4 (201 Views)

Re: DDMi - Discover DHCP Clients w/o DHCP Server Discovery

I manage about 32,000 devices discovered, and 14,000 devices inventoried without utilizing my DHCP servers / arp tables / etc. I basically have it set to do it's normal discovery: ping sweeps / etc.

I'm sure that if I had access to ARP tables, the discovery process would work a little better, but I have nothing to complain about and the DDMI server functions just fine for me.

DDMI is set to ping sweep subnets that you define in your device groups. I have about 75 device groups with a bunch of subnets defined. At 30 pings a second, it takes 90 minutes to get through my 'known' network. DDMI will find the new ips for devices if they change, merge them accordingly, etc.

My experience is that it is NOT critical to the success at all of the DDMI.

~Jeff
Esteemed Contributor
Matthew Darwin
Posts: 262
Registered: ‎08-07-2008
Message 3 of 4 (201 Views)

Re: DDMi - Discover DHCP Clients w/o DHCP Server Discovery

If you're scanning like Jeff said, the devices will merge based on the scan.

If you are not scanning and don't have SNMP enabled on something that gives you ARP tables, you will definitely get a bunch of duplicate devices.

BTW> You need at least 1 device in the network (other than the DDMI server itself) to have SNMP enabled so that aging works properly.
Contributor
mapu39
Posts: 14
Registered: ‎05-08-2007
Message 4 of 4 (201 Views)

Re: DDMi - Discover DHCP Clients w/o DHCP Server Discovery

Hi Matthew,

yes I know all that but the prob is that we could not under any circumstances turn snmp on. It´s a Security policy at the customer, that snmp is off.

Are there any alternatives without snmp, or could I extend the expiry value or something else ?

Thank you for your great help !

Rgds,
Matthias
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