Ethernet LAN Change MAC address

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Subject Author Date
Change MAC address GreaserX 06-20-07
---> Re: Change MAC address Robert Redelmei...06-20-07
  `--> Re: Change MAC address glen herrmannsf...06-20-07
Posted by GreaserX on June 20, 2007, 7:19 am
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I have a question geared toward anyone familar with networking. I needto
change my IP address and/or change my MAC address. Does anyone know that this
is possible? If this is possible, please tell me how you are able to do it.
Can I use some shareware software or must I purchase a specialized network
card for this task. I read a website that sells hardware on
http://www.sdadapters.com and I also found software to use like AMAC or
Macshift. I would prefer to not spend any money. Does anyone have any
experience at all with these solutions? Thanks!! Please email me.


Posted by Robert Redelmeier on June 20, 2007, 9:52 am
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> I needto change my IP address and/or change my MAC
> address. Does anyone know that this is possible?

It is, but highly dependant on exact configuration. Some
ethercards can have MACs reprogrammed, others cannot. But beware
-- some ISPs use MAC as part of their authentication sequence.

IPs are a separate subject. They are given to you by your
ISP, usually via DHCP but occasionally static or BOOTP.
Some ISPs give you a different IP every time you login,
others will try to keep the same one for months. There is
relatively little you can do.

> Thanks!! Please email me.

It's impolite to ask for email from a public forum.
And how can you expect replies to an incomplete address?

-- Robert


Posted by Walter Roberson on June 20, 2007, 10:45 am
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>Some
>ethercards can have MACs reprogrammed, others cannot. But beware
>-- some ISPs use MAC as part of their authentication sequence.

>IPs are a separate subject. They are given to you by your
>ISP, usually via DHCP but occasionally static or BOOTP.
>Some ISPs give you a different IP every time you login,
>others will try to keep the same one for months.

Some ISPs determine whether the same system is DHCP'ing by examining
the MAC address, and thus will assign a different DHCP'd address
if the user's MAC address changes. That's about the only reason
to change one's MAC address, since nothing past the first ISP hop
sees the MAC in the IP packets. (Though I've read somewhere that there
are techniques for java or javascript [not sure which] to retrieve the
MAC. I do not have the experience to confirm or deny this.)

Posted by glen herrmannsfeldt on June 20, 2007, 2:04 pm
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Robert Redelmeier wrote:


>>I needto change my IP address and/or change my MAC
>>address. Does anyone know that this is possible?

> It is, but highly dependant on exact configuration. Some
> ethercards can have MACs reprogrammed, others cannot. But beware
> -- some ISPs use MAC as part of their authentication sequence.

As far as I know, all allow software programmability of the MAC
address at startup. They don't all supply the software to do it.

The easiest way is to buy a new NIC. They are cheap enough now.

> IPs are a separate subject. They are given to you by your
> ISP, usually via DHCP but occasionally static or BOOTP.
> Some ISPs give you a different IP every time you login,
> others will try to keep the same one for months. There is
> relatively little you can do.

IP addresses are technically not part of the ethernet newsgroup.

To change IP address you need to talk to the administrator of the
network you are on. In a school or work environment that will often
be a local (internal) network. For home that will be your ISP.

-- glen


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