Groups > alt.folklore.computers > #225900

Re: What happens to old MAC assignments?

From	ted@loft.tnolan.com (Ted Nolan <tednolan>)
Newsgroups	alt.folklore.computers
Subject	Re: What happens to old MAC assignments?
Date	2024-07-19 16:02 +0000
Organization	loft
Message-ID	<lfvh1fFjhohU3@mid.individual.net> (permalink)
References	<v7bd85$14q$1@reader1.panix.com> <v7bsvo$2ighc$5@dont-email.me> <v7cm85$dcb$2@tncsrv09.home.tnetconsulting.net>

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In article <v7cm85$dcb$2@tncsrv09.home.tnetconsulting.net>,
Grant Taylor  <gtaylor@tnetconsulting.net> wrote:
>On 7/18/24 15:12, Marco Moock wrote:
>> Address conflicts can occur.
>
>Yes they can.
>
>No they SHOULDN'T
>
>> People must not assume that a MAC address is really unique.
>
>People SHOULD be able to assume that the MAC is unique on any given 
>network segment.
>
>N.B.
>  - the use of RFC "SHOULD" vs "MUST".
>  - not all vendors adhere to the standards
>
>> Ethernet MAC addresses are always 48 bit.
>
>The only thing that I think which can claim to be Ethernet that doesn't 
>use a 48-bit MAC address is 3 Mbps experimental Ethernet which I believe 
>used 8-bit MAC addresses. I know that Fibre Channel uses different 
>things.  I thought Token Ring used something else, but it seems like it 
>also uses 48-bit MAC addresses.
>

On Suns back in the day, you could set any MAC address you liked
(of course the default was the one in the ROM).  This could be handy
for spoofing devices that were gone but still expected at a certain
MAC for whatever reason.  You could definitely get yourself in trouble
though, as when we switched out our ISP's router for a Sun IPC, spoofing
the MAC so their net would let it in.  (I think we were doing something
with port mapping their box didn't support, but I forget exactly why
we thought it was necessary).  Worked fine for months and then they did
some sort of upgrade...
-- 
columbiaclosings.com
What's not in Columbia anymore..

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What happens to old MAC assignments? David Lesher <wb8foz@panix.com> - 2024-07-18 15:44 +0000
  Re: What happens to old MAC assignments? Gordon Henderson <gordon+usenet@drogon.net> - 2024-07-18 16:12 +0000
    Re: What happens to old MAC assignments? Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-07-19 01:08 +0000
  Re: What happens to old MAC assignments? Andy Burns <usenet@andyburns.uk> - 2024-07-18 17:14 +0100
    Re: What happens to old MAC assignments? David Lesher <wb8foz@panix.com> - 2024-07-21 14:39 +0000
  Re: What happens to old MAC assignments? Marco Moock <mm+usenet-es@dorfdsl.de> - 2024-07-18 22:12 +0200
    Re: What happens to old MAC assignments? Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-07-19 01:07 +0000
    Re: What happens to old MAC assignments? Grant Taylor <gtaylor@tnetconsulting.net> - 2024-07-18 22:23 -0500
      Re: What happens to old MAC assignments? Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-07-19 08:11 +0000
        Re: What happens to old MAC assignments? Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-07-19 08:14 +0000
          Re: What happens to old MAC assignments? Grant Taylor <gtaylor@tnetconsulting.net> - 2024-07-19 19:26 -0500
          Re: What happens to old MAC assignments? Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-07-20 09:01 +0000
      Re: What happens to old MAC assignments? Marco Moock <mm+usenet-es@dorfdsl.de> - 2024-07-19 16:08 +0200
        Re: What happens to old MAC assignments? Grant Taylor <gtaylor@tnetconsulting.net> - 2024-07-19 19:31 -0500
          Re: What happens to old MAC assignments? Marco Moock <mm+usenet-es@dorfdsl.de> - 2024-07-23 12:52 +0200
            Re: What happens to old MAC assignments? R Daneel Olivaw <Danny@hyperspace.vogon.gov> - 2024-07-23 14:11 +0200
              Re: What happens to old MAC assignments? Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-07-24 00:21 +0000
                Re: What happens to old MAC assignments? Grant Taylor <gtaylor@tnetconsulting.net> - 2024-07-24 00:00 -0500
                Re: What happens to old MAC assignments? Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-07-24 23:46 +0000
                Re: What happens to old MAC assignments? Grant Taylor <gtaylor@tnetconsulting.net> - 2024-07-24 21:52 -0500
                Re: What happens to old MAC assignments? R Daneel Olivaw <Danny@hyperspace.vogon.gov> - 2024-07-24 11:36 +0200
                Re: What happens to old MAC assignments? Lars Poulsen <lars@beagle-ears.com> - 2024-07-24 08:28 -0700
                Re: What happens to old MAC assignments? R Daneel Olivaw <Danny@hyperspace.vogon.gov> - 2024-07-24 20:52 +0200
                Re: What happens to old MAC assignments? Lynn Wheeler <lynn@garlic.com> - 2024-07-24 14:07 -1000
      Re: What happens to old MAC assignments? ted@loft.tnolan.com (Ted Nolan <tednolan>) - 2024-07-19 16:02 +0000
        Re: What happens to old MAC assignments? Bob Eager <news0009@eager.cx> - 2024-07-19 21:47 +0000
        Re: What happens to old MAC assignments? Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-07-19 22:53 +0000
        Re: What happens to old MAC assignments? Grant Taylor <gtaylor@tnetconsulting.net> - 2024-07-19 19:35 -0500
          Re: What happens to old MAC assignments? Marco Moock <mm+usenet-es@dorfdsl.de> - 2024-07-23 12:54 +0200
            Re: What happens to old MAC assignments? Grant Taylor <gtaylor@tnetconsulting.net> - 2024-07-24 00:01 -0500
          Re: What happens to old MAC assignments? Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-07-24 00:22 +0000
      Re: What happens to old MAC assignments? scott@slp53.sl.home (Scott Lurndal) - 2024-07-19 16:20 +0000
        Re: What happens to old MAC assignments? Grant Taylor <gtaylor@tnetconsulting.net> - 2024-07-19 19:36 -0500
      Re: What happens to old MAC assignments? Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-07-19 22:57 +0000
        Re: What happens to old MAC assignments? Grant Taylor <gtaylor@tnetconsulting.net> - 2024-07-19 19:39 -0500
          Re: What happens to old MAC assignments? Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-07-20 00:53 +0000
            Re: What happens to old MAC assignments? Grant Taylor <gtaylor@tnetconsulting.net> - 2024-07-19 21:51 -0500
              Re: What happens to old MAC assignments? Marco Moock <mm+usenet-es@dorfdsl.de> - 2024-07-23 12:57 +0200
                Re: What happens to old MAC assignments? Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-07-24 00:26 +0000
                Re: What happens to old MAC assignments? Grant Taylor <gtaylor@tnetconsulting.net> - 2024-07-24 00:04 -0500
          Re: What happens to old MAC assignments? "Kurt Weiske" <kurt.weiske@realitycheckbbs.org.remove-hqx-this> - 2024-07-20 08:44 -0700
            Re: What happens to old MAC assignments? Grant Taylor <gtaylor@tnetconsulting.net> - 2024-07-20 12:14 -0500
              Re: What happens to old MAC assignments? Marco Moock <mm+usenet-es@dorfdsl.de> - 2024-07-23 12:59 +0200
                Re: What happens to old MAC assignments? Ahem A Rivet's Shot <steveo@eircom.net> - 2024-07-23 12:39 +0100
                Re: What happens to old MAC assignments? Marco Moock <mm+usenet-es@dorfdsl.de> - 2024-07-23 21:40 +0200
                Re: What happens to old MAC assignments? ted@loft.tnolan.com (Ted Nolan <tednolan>) - 2024-07-23 21:38 +0000
                Re: What happens to old MAC assignments? Marco Moock <mm+usenet-es@dorfdsl.de> - 2024-07-24 11:42 +0200
                Re: What happens to old MAC assignments? Lars Poulsen <lars@beagle-ears.com> - 2024-07-24 08:29 -0700
                Re: What happens to old MAC assignments? R Daneel Olivaw <Danny@hyperspace.vogon.gov> - 2024-07-24 20:55 +0200
                Re: What happens to old MAC assignments? Grant Taylor <gtaylor@tnetconsulting.net> - 2024-07-24 00:08 -0500
            Re: What happens to old MAC assignments? Andy Burns <usenet@andyburns.uk> - 2024-07-20 18:14 +0100
            Re: What happens to old MAC assignments? Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-07-21 01:11 +0000
    Re: What happens to old MAC assignments? scott@alfter.diespammersdie.us (Scott Alfter) - 2024-07-19 15:08 +0000
      Re: What happens to old MAC assignments? Grant Taylor <gtaylor@tnetconsulting.net> - 2024-07-19 19:41 -0500
      Re: What happens to old MAC assignments? Marco Moock <mm+usenet-es@dorfdsl.de> - 2024-07-23 13:00 +0200
        Re: What happens to old MAC assignments? Grant Taylor <gtaylor@tnetconsulting.net> - 2024-07-24 00:10 -0500
    Re: What happens to old MAC assignments? David Lesher <wb8foz@panix.com> - 2024-07-21 14:47 +0000
      Re: What happens to old MAC assignments? Andy Burns <usenet@andyburns.uk> - 2024-07-21 16:43 +0100
        Re: What happens to old MAC assignments? Ahem A Rivet's Shot <steveo@eircom.net> - 2024-07-21 17:15 +0100
      Re: What happens to old MAC assignments? Grant Taylor <gtaylor@tnetconsulting.net> - 2024-07-21 14:15 -0500
      Re: What happens to old MAC assignments? drb@ihatespam.msu.edu (Dennis Boone) - 2024-07-22 03:23 +0000
      Re: What happens to old MAC assignments? Marco Moock <mm+usenet-es@dorfdsl.de> - 2024-07-23 13:01 +0200
  Re: What happens to old MAC assignments? drb@ihatespam.msu.edu (Dennis Boone) - 2024-07-18 20:43 +0000
    Re: What happens to old MAC assignments? Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-07-19 01:06 +0000
      Re: What happens to old MAC assignments? drb@ihatespam.msu.edu (Dennis Boone) - 2024-07-19 01:19 +0000
    Re: What happens to old MAC assignments? Grant Taylor <gtaylor@tnetconsulting.net> - 2024-07-18 22:12 -0500
  Re: What happens to old MAC assignments? Bud Frede <frede@mouse-potato.com> - 2024-07-26 08:42 -0400

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