Can't Access Internet after changing MAC
 

i changed my MAC address with ifconfig successfully. ifconfig -a wlan0 outputted the new MAC address but the problem is i can't access the internet ( web pages won't load, etc... ) so i changed the MAC address back to it's original and everything worked fine. anyone know why this is?

thanks for your help.

This depends a lot on your network environment. If you're at a college campus, for example, you could easily have your account associated with your MAC address, and therefore changing it could easily prevent you from connecting. If you're connected via cable or something from your home or something, I wouldn't think that your MAC would matter. I think you have to give more details before someone can help you.

Cable Modems use the MAC address for requisitioning. If you were to purchase a Linksys cable router, for example, you would need to register the device in the web interface before accessing the Internet.

i am not using a cable modem connection it is a dsl connection .. rather i am connecting to the internet via a wireless adapter through an access point (router). the router is set to accept all incoming wireless and has no MAC address restrictions yet i am unable to connect through the router to the net upon changing the HW Address via ifconfig.

Remember the joke about the patient who tells the doctor that his knee hurts when he bends it like this. The doctor tells him, "well then don't bend it that way".

Why do you need to change the MAC address on your interface? I don't see what advantage you could get from changing the MAC address. Did you change the MAC address after you had a wireless connection? Perhaps there is some MAC/IP address table that the access point uses that needs to be flushed before it will work. From the access point's point of view (that wasn't a pun) it might look like two devices are using the same IP address.

My best guess is that there is some type of MAC address filtering being used to help defend against spoofing.

go whitesox!
 

Trust me when I say there are no MAC Spoofing Filtering there are no filtering whatsoever set on the router I checked it for myself. The reason I wish to spoof the MAC Address is because I am able to do so in Windows using MAC Makeup without a problem and access the internet. It just bothers me that I can not get it working under Linux by manually changing the MAC address with ifconfig nor with MAC Address spoofing programs for Linux which I've tried. The problem here isn't that I can not change the MAC Address because I can - changing the MAC Address is not a problem in Slackware it's easy as pie. But getting online is.

I just don't understand what the difference can be between MAC Spoofing under Linux and Windows. While in Windows I can access the internet after a MAC spoof and in Linux I can't after spoofing the MAC.

On a side note. Using MAC Makeup under windows and spoofing the MAC Address causes no problem when I connect to the internet through the router. The DHCP Table even lists my previous MAC Address upon connection including my new spoofed MAC Address so I don't think the the MAC/IP tables has anything to do with this problem.

Any ideas??

Another reason is I wish to completely switch to Slackware from Windows XP/VMware(slack) and the very idea that something works under Windows and not under Linux really gets to me.. :-|

Yes but *why* are you spoofing your MAC? You still haven't answered that question.

My best guess as to why it's not working is a buggy driver for the NIC.
Are you doing it with ndiswrapper?

--Shade

why?
 

does it really matter why? i hate people who answer questions with a question. what reason do you even have to ask me such a question being that i am capable of changing my mac address successfully and connect to the internet from windows. it really doesn't matter why i wish to change my mac address - the question was why changing resulted in no internet connection from within slackware.

and i do believe i answered your question as to why i wish to change my mac address because it can be done who wants their mac address being publicized i certainly don't, being a very security minded person i would hate for anyone to get ahold of my mac address and abuse it.

linux to me is a learning process and the reason i brought up the question of why mac address spoofing resulted in no internet connection was plain curiousity if you can't understand that much then i truly don't understand why your even using linux in the first place you might as well go back to using windows and conform to the masses of idiots who are bound by an operating system that does everything for them.

Maybe.. (just maybe) after changing your MAC address you didn't try to get a new IP address from the access point?

as far as i know the ip address assigned to the mac address doesn't change or if it did it's not really a huge difference being that the ap has it's main ip address and the computers connecting to the AP all have address within the 192.168.1.* range while the AP has a regular ip address like 205.35.23.11 (just an example) if my goal was to change the ip address then i would spoof the ip address which really isn't my goal.. my goal is only to spoof the mac address.

digimafia, I totally support your point of view. BTW, I also tried to change my mac address and did not succeed to access my router afterwards. Neither did I insist on finding a solution, because I really had no use for it.

So why did I do it? Out of intellectual curiosity. Like most of what I do with my computer, or Linux for that matter. If I used my computer only for those tasks I really need it for, I'd certainly be running MacOS or Windows. But especially Slackware users should give in to intellectual curiosity IMHO.

Digimafia, can you post the commands sequence that you are trying to enter in your system? Sometimes you need to ifconfig down the interface, change de MAC and ifconfig up again...

Another point is that the 802.11 protocol can have more than two MAC addresses in a single package (generally three MAC addresses). So, if your wireless module do not correct support these MACs. Your MAC will not work...

I've been doing some tests and the problem appears when I change the MAC address while leaving the IP address identical. If however I change both the MAC address and the IP address, the connection to the router works.
So it appears to me that the router is "upset" by the fact that in its ARP table, the same IP address is associated to a different MAC address.

Try changing both addresses at the same time and tell us if that works.

digimafia: yes, but you have to get your ip address registered with your mac, in the ap's new routing table. otherwise the ap won't recognise your new mac and think it's an outsider trying to spoof your ip or something, just like what uselpa says.

luiz might have a point ;)