Experts! I am running a Windows XP Pro/Server 2003 AD environment with 200+ users on a network built with Nortel 325-24G switches. I have a MAC address that I would like to block from gaining access to the network. I am trying to narrow down where the computer is and my plan is to cut off the network access and find the user screaming the loudest. For the points, provide how can I block a particular MAC address? Thank you!
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I am running network auditing software from spiceworks which is amazing and free!! I found the MAC and I am sure I could have one of the helpdesk techs find the pc but I would really like to learn how to do this (block MAC address) and this is a good opportunity. But yes, you are dead-on. I found the port on the Nortel device and know which floor it is and verified the pc name using the DHCP scope.
I am working on finding the state contact that sold us this "amazing" hardware. I found something about MAC security but before I start blocking ports and MAC's, I would like to make sure I'm not updating my resume as a result of my on the fly "testing". Hopefully someone that knows Nortel like I know COD4 will post something promising. Otherwise I will award you the points and begin my moaning about this hardware.
Thanks again and take care!
We were a Nortel shop - we forklifted the network about a year ago to Cisco Catalysts 3750 and 6500's - from Passport 8000's and Baystack 450's. We never got into the 325's.
That being said, ACL's are more for layer 3 devices - routers or layer 3 switches. What you're wanting to do is filter at the switch layer - layer 2. This will be a real PITA for you. As stated, you could implement mac based filtering - basically NAC (pronounced nack) - Network Admission Control - or 802.1x.
It might be eaiser to do MAC based vlans - you'd have to put all the MACs that plug into the switch into the config and then drop them into the appropriate vlan. Then with the offender - drop them into a quarantine vlan - one which doesn't communicate with anyone else. As I said, this would be a big pain in the Assets - are you sure you want to do this? You're talking about re-architecting your network because of one machine. Offhand, it sounds like whatever the offense is, it's best handled by administrative/managerial practices - someone with clout needs to give them a smackdown.
Oh - and you run Nortel equipment and don't have a service plan!?!? That should be your main concern & priority!
pseudocyber- Well, I was hoping that it could be contained on the switch and not on the router. Makes sense, just hoping it wasn't the harder path. Looks like I will fold up shop on this project. You provided outstanding information. Thank you! Yes the Nortel switches that were purchased from the state were supposed to be covered by the state's Nortel contract. Evidentally that is not the case as this little demonstration discovered. Thank God it wasn't a REAL critical issue or we would be in the papers. I am working with two vendors now to get a service contract in place to head-off any other issues.
Take care!
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by: brittonvPosted on 2007-12-26 at 10:57:53ID: 20530342
While I can't answer your question, have you tried to figure out who it is? You can get an idea as to what kind of device it is by searching on it's MAC address:
http://www.coffer.com/mac_
And while I don't have any Nortel experience, I have yet to see a managed switch that didn't tell you what port a MAC address is on. Have you traced it back that way or pulled the plug?