[K12OSN] deny IP based on MAC address....how?

Christopher K. Johnson ckjohnson at gwi.net
Mon Oct 4 02:20:19 UTC 2004

Jim Hays wrote:

>try looking at
>man dhcpd
>and serch for deny
>That may have the info you want.
>Quoting David Trask <dtrask at vcs.u52.k12.me.us>:
>>Hi all,
>>I have a situation....I have an IP address that I believe is infected with
>>a worm that putting significant traffic on my network.  The IP address is
>>internal and I don't for the life of me know where it is.  I've tried
>>everything to find it.  I know the MAC address from the logs on my DHCP
>>server....what I'd like to do is prevent that MAC address from even
>>getting an IP address.   Is this possible?  I'm using an FC 1 server as my
>>DHCP server (that's all that particular server does...just DHCP).  I have
>>no desire to populate my entire dhcpd.conf file with all the MAC addresses
>>in my building....there's too many.  What I simply want to do is deny
>>giving an IP address to a particular machine (whose MAC address I
>>know)....and/or deny access to my network (from inside) to that IP
>>address.  (I've statically assigned that IP to that MAC in my dhcpd.conf
>>so I can at least track it, but now I need to shut it down)  Any ideas?
You can also get a clue what the machine is named, or even perhaps who 
is logged onto it:
nmblookup -r -A ip_addr_you_assigned

   "Spend less!  Do more!  Go Open Source..." -- Dirigo.net
   Chris Johnson, RHCE #807000448202021

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