change MAC address can change IP address of a machine?

Discussion in 'Wireless Internet' started by apngss, Sep 30, 2005.

  1. apngss

    apngss Guest

    Is there any way to change the MAC address of a machine? IP address is
    assigned by ISP. My understanding is that IP address is based on the
    MAC address of a machine, is that correct concept?

    please advise. thanks!!
    apngss, Sep 30, 2005
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  2. :Is there any way to change the MAC address of a machine?

    Of most machines, Yes.

    :IP address is assigned by ISP. My understanding is that IP address is
    :based on the MAC address of a machine, is that correct concept?

    It might be, it might not be, it depends on the ISP. Some ISPs know
    what port number you are using in their equipment and assign the
    address on that basis.

    Some ISPs encrypt traffic to the modem based upon your MAC address,
    so changing your MAC address might get you nothing.

    The ISPs that do use MAC as a factor often register the MAC against the
    account, and you might have to find the MAC of a valid subscriber
    to change the IP you get. But ISPs tend to have protections against that.
    Walter Roberson, Sep 30, 2005
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  3. On 30 Sep 2005 10:25:22 -0700, wrote:

    cross posted to 4 newsgroups. Gosh, this must be terribly important.
    Rubbing my crystal ball, I deduce that you're using some Linux or
    Windoze mutation. Of course, all operating system are the same so the
    following instructions should work no matter what you're using.

    Here's an article that covers most of the methods.

    /etc/init.d/networking stop
    ifconfig eth0 hw ether 11:22:33:44:55:66
    /etc/init.d/networking start

    Correct. If you're a spammer and want to cover your tracks, this is a
    way of forcing a change to your dynamically assigned IP address. It
    will also drive the ISP nuts, trash their log files, and possibly
    mangle their RADIUS authentication (if the MAC address is used for
    authentication). If you happen to land on a MAC address that's
    already in use at the ISP, traffic will stop for both machines. Do
    this often enough and you should get the ISP's attention and receive
    your due rewards.
    Free advice. Don't do it.
    Jeff Liebermann, Sep 30, 2005
  4. apngss

    strutsng Guest

    how to change the MAC address then?
    strutsng, Sep 30, 2005
  5. |>:In article <>,
    |>:Is there any way to change the MAC address of a machine?

    |>:Of most machines, Yes.

    |how to change the MAC address then?

    You have cross-posted this to a variety of newsgroups, including
    - one for Windows XP (which runs only on systems with the Intel Pentium
    instruction set, as far as I know)
    - one for wireless devices, many of which use specialized CPUs and
    specialized network cards
    - a linux networking newsgroup; linux runs on a quite wide variety of
    devices; and
    - a group devoted to the TCP and UDP protocol suite.

    Considering the multitude of hardware devices implied by your choice
    of newsgroups, one must presume that you are looking for some
    standard TCP or UDP or ICMP packet that one can send which will
    trigger the change of MAC address.

    No such TCP / UDP / ICMP packet exists.

    No POSIX standard socket call exists that would change MAC addresses

    All facilities to change MAC addresses are specific to the combination
    of hardware and OS that one has. I thus recommend that you post
    to a newsgroup specific to your hardware and software, stating the
    equipment you have, and soliciting information there. Or, better yet,
    google for the information, as it is readily available for common
    equipment + software combinations.
    Walter Roberson, Sep 30, 2005
  6. apngss

    James Knott Guest

    It is possible to change the MAC address on most NICs. The IP address, in
    IPv4, is not related to the MAC address, but in the case of DHCP, assigned
    to one. In IPv6, the MAC address forms part of the IP address.
    James Knott, Sep 30, 2005
  7. Many IPv6 address contain real 48-bit IEEE addresses, but many others
    do not. See RFC 2373 or look at some IPV6 DNS RRs. For an example
    of the latter, consider:

    % host -t aaaa has IPv6 address 2001:888:20ee::6277

    Vernon Schryver
    Vernon Schryver, Sep 30, 2005
  8. apngss

    Attils Guest

    ha scritto:
    Look for SMAC 1.2
    Attils, Jan 6, 2006
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