Granted that mac filtering keeps crap out but bear in mind the REAL threat is not accidental users of your network but more so intelligent criminals who will go straight for the kill with a spoofed mac, pick up a dhcp address, then mine your data by further penetrating your applications. Is mac filtering an effective layer of security? Or is it just another administrative burden that gives your boss better qos by ensuring unauthorised users are not borrowing your network? Am just trying to promote thought outside the box here - anyone intent on getting access to your network via wireless is not going to simply plug in a linksys AP and set alarm bells ringing - they are very likely to use a custom AP with spoofed mac or try and install a usb AP on an existing device in order to conceal their tracks.
Rgds Tim Sent from my BlackBerry® wireless device -----Original Message----- From: Adam Powers <[EMAIL PROTECTED]> Date: Wed, 28 Mar 2007 10:40:53 To:<[EMAIL PROTECTED]>,Adam Graham <[EMAIL PROTECTED]>,<[EMAIL PROTECTED]>,"[EMAIL PROTECTED] Com" <[email protected]> Subject: Re: Wired detection of rogue access points "Filtering by MAC gives you no additional security whatsoever, period" Meh, this is simply not true. My home AP might is plenty secure from my SOHO technology noob neighbors with MAC filtering - few, if any, of them even know what an "AP" is much less "MAC spoofing". Having said that filtering technologies such as MAC filtering are far too difficult to manage given the relatively small security return provided and as such should be avoided given the fact that other superior authentication and access control mechanisms exist. On 3/26/07 7:24 PM, "[EMAIL PROTECTED]" <[EMAIL PROTECTED]> wrote: > Filtering by MAC gives you no additional security whatsoever, period. MAC > addresses can be easily spoofed and although your solution may assist in > spotting misconfigurations a determined intruder will get straight through.... > > Sent from my BlackBerry® wireless device > > -----Original Message----- > From: "Adam Graham" <[EMAIL PROTECTED]> > Date: Mon, 26 Mar 2007 15:52:21 > To:<[email protected]> > Subject: RE: Wired detection of rogue access points > > First off is it even possible to buy a laptop that does not have wifi built > in? > > I have set up an automated scan looking for MACs. If the MAC does not appear > on my list I drop its packets in the IPTabes FW. It's rather simple to do. > The main thing I do that seems to work the best is the APs are un-trusted > and therefore stuck out in the DMZ. Before one can get to network resources > they need to open the VPN client after connecting to the AP. > > A simple way to handle MACs with IPTables (NOTE: simple rule if you need > more instruction I can send it to you or just the complete iptable script): > > Let's create 2 text files: > /tmp/whiteist > /tmp/blackist > > Insert into whiteist 00:06:25:2E:56:A0 > Insert into blackist 00:06:25:2E:56:E1 > > > Add following to your IPTabes script > TABLES = "filter nat mangle" > iptables = /sbin/iptables > touch /tmp/whiteist > touch /tmp/blackist > WHITELIST = `cat /tmp/whiteist | awk '{print $1}' > BLACKLIST = `cat /tmp/blackist | awk '{print $1}' > > # Forward good MACs > $iptables -t filter -I FORWARD 1 -m mark --mark 0x42 -j ACCEPT > > # mark all packets from the good macs > for MAC in $WHITELIST ; do > $iptables -t mangle -I PREROUTING -m mac --mac-source $MAC -j MARK > --set-mark 0x42 > done > > # drop all packets from the good macs > for MAC in $BLACKLIST ; do > $iptables -t mangle -I PREROUTING -m mac --mac-source $MAC -j DROP > done > > > > > > ------------------------------------------------------------------------ > Test Your IDS > > Is your IDS deployed correctly? > Find out quickly and easily by testing it > with real-world attacks from CORE IMPACT. > Go to > http://www.coresecurity.com/index.php5?module=Form&action=impact&campaign=intr > o_sfw > to learn more. > ------------------------------------------------------------------------ > -- Adam Powers Chief Technology Officer Lancope, Inc. c. 678.725.1028 e. [EMAIL PROTECTED]
