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| Subject: | Re: Dhcp security |
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| Date: | Wed, 26 Jan 2005 16:58:41 -0700 |
Another interesting idea that is becoming popular is a process called end-point security. End-point security is kind of a vague term that implies the end-point (or host) needs to conform to a certain policy in order to be allowed network resources. Basically so far it boils down to some method of quarantining devices until they pass a battery of tests. After a device passes the test it is allowed access. There are quite a few commercial products and free software that follows the end-point security model. Off the top of my head I can think of: Cisco NAC (1) Microsoft NAP (Might not be released yet, maybe in Longhorn??) (2) Microsoft NAQC (Available in Windows 2003 server) (2) Perfigo CleanMachines (Bought by Cisco but is different than NAC) (3) StillSecure SafeAccess (4) 802.1x (Free) (5) NetReg (Free) (6) These products implement end-point security in different ways. Some will setup a quarantine DHCP scope that will host the devices until they are compliant then allow the device to obtain a real lease. Of course DHCP quarantining can be defeated with static IP addresses but it would stop the honest user infected with worms etc... The other main method of quarantining is to utilize either VLANS or private VLANS on switches to segregate the end-point device until it is tested and compliant. Then the end-point device will be moved into the proper VLAN. This method is more secure in regards to trying to circumvent the quarantining process but it is much more involved to implement. Another method which is a little different than the other two is more of a "Scan and Block" method. This is a device that is inline between the assets you want to protect and the devices you want to screen. A device cannot pass the inline device until it is compliant. 802.1x is a standard of authentication network connections via EAP over Ethernet which is not a quarantining method per se but it would prevent anyone from connecting to your LAN that does not have a password and username.... I hope this answers what I think is your issue problem of "How do I protect my internal assets from devices that might be "unclean" on my internal networks?" 1)http://www.cisco.com/en/US/netsol/ns466/networking_solutions_sub_solution_ home.html 2)http://www.microsoft.com/windowsserver2003/technologies/networking/nap/def ault.mspx 3)http://www.perfigo.com/products/index.html 4)http://www.stillsecure.com/products/sa/ 5)http://www.microsoft.com/windows2000/server/evaluation/news/bulletins/8021 xclient.asp 6)http://www.netreg.com Blabbing on and on.... -- Cory Stoker On 1/21/05 7:33 AM, "Shawn Wall" <sjwall@shaw.ca> wrote:
You could reserve every IP address on you DHCP server with MAC addresses from you known user base. A pain in the hump for sure. If you have network switches capable of L2 security you could lock down the ports to prevent unauthorized MAC addresses from connecting to the network to begin with. HTH -----Original Message----- From: Paul Aviles [mailto:paviles@adjoined.com] Sent: Wednesday, January 19, 2005 3:30 PM To: focus-ms@securityfocus.com Subject: Dhcp security I have a weird question maybe. Is there a way to prevent our DHCP from giving leases to computers not in our domain? I don't want anyone that walks in to just connect and have the possibility of a network viruses getting loose. Is this possible? My setup is a typical AD 2K environment, simple domain no empty root. Thanks Paul
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