change MAC address can change IP address of a machine?

[apngss]

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!!

 

[Walter Roberson]

: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.

 

[Jeff Liebermann]

On 30 Sep 2005 10:25:22 -0700, (e-mail address removed) 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.
http://en.wikipedia.org/wiki/MAC_address

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

Windoze:
http://www.nthelp.com/NT6/change_mac_w2k.htm
http://www.klcconsulting.net/smac/

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?

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.

please advise. thanks!!

Free advice. Don't do it.

 

[strutsng]

how to change the MAC address then?

 

[Walter Roberson]

|>:In article <[email protected]>,
|>: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
either.

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.

 

[James Knott]

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?

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.

 

[Vernon Schryver]

In IPv6, the MAC address forms part of the IP address.

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 dcc.dcc-servers.net
dcc.dcc-servers.net has IPv6 address 2001:888:20ee::6277


Vernon Schryver (e-mail address removed)

 

[N. Miller]

Is there any way to change the MAC address of a machine?

Generally, yes; but...

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?

That depends entirely on the way an ISP has set up authentication to their
network. In the case of cable companies, generally, yes; but you often have
to register the MAC with the provider. If you change your MAC, and you
don't register the change, the provider may do something akin to Comcast,
sticking you in their "Walled Garden" until you register the change.

Looking at your posting headers:

NNTP-Posting-Host: 69.107.74.225

Sam Spade tells me:

| 10/01/05 01:28:41 dns 69.107.74.225
| nslookup 69.107.74.225
| Canonical name: adsl-69-107-74-225.dsl.pltn13.pacbell.net
| Addresses:
| 69.107.74.225

If your posting ISP account is the one you are asking about, you are out of
luck. SBC does not associate IP addresses to MAC addresses. Authentication
is via PPPoE, and IP address assignment is by DHCP. Your IP address will
change when the DHCP lease expires, unless you are online during the period
when your PPPoE client is requesting a lease renewal. You can force an IP
address change by terminating the PPPoE session, and waiting for several
minute before restarting it. I have, on occasion, gotten the same IP
address when restarting the PPPoE session within a minute, or so, of
termination.

 

[Attils]

(e-mail address removed) ha scritto:

how to change the MAC address then?

Look for SMAC 1.2