RE: Comparing hosts on a network to text file

[Dave Kleiman <dave () davekleiman com>]

Andi,

You could create a database of the known and compare separate tables of the current active, leaving the results of any 
not listed in the known.

Respectfully,

Dave Kleiman - http://www.ComputerForensicsLLC.com - http://www.computerforensicsexpertwitnesses.com/

4371 Northlake Blvd #314
Palm Beach Gardens, FL 33410
561.310.8801 


-----Original Message-----
From: listbounce () securityfocus com [mailto:listbounce () securityfocus com] On Behalf Of Morris, Andi
Sent: Tuesday, August 07, 2012 10:38
To: security-basics () securityfocus com
Subject: Comparing hosts on a network to text file

Hi all,
I’m looking to create a script, or use something already in existence to scan a network for hosts, returning the mac 
addresses active on the network.  The script should then compare the mac addresses discovered to a prepopulated text 
file and somehow notify me of any discrepancy.

I’d imagine nmap would be the tool I’m after.

The scenario is:
I have a network that has a filled DHCP scope.
When a user registers a device with us we assign them an IP address on the Windows DHCP server.
We are trying to avoid users manually giving themselves an IP address from this range and gaining access.
My plan was to have a script poll the network every ‘n’ minutes to compare the mac addresses on the network to those 
that we have reserved IPs for and to email the details of any rogue clients to a designated mailbox .

Does this sound feasible and does anyone know of a tool that would already exist for this before I spend hours learning 
and configuring nmap (not time badly spent I admit).

Cheers,
Andi

---------------------------------------------------------------
Andi Morris
Technical Security Analyst
Systems and Communications Services
Information Services Division
Cardiff Metropolitan University
Cardiff
Wales
CF5 2YB

02920 205720
--------------------------------------------------------------

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