Date: Fri, 20 Feb 1998 10:39:42 -0500 From: Norman C Rice <nrice@emu.sourcee.com> To: Leif Neland <leifn@image.dk> Cc: freebsd-questions@FreeBSD.ORG Subject: Re: hostid equals Ethernet address or IP address ? Message-ID: <19980220103942.16439@emu.sourcee.com> In-Reply-To: <21b_9802201202@swimsuit.swimsuit.roskildebc.dk>; from Leif Neland on Fri, Feb 20, 1998 at 08:43:05AM %2B0100 References: <Pine.BSF.3.96.980219153649.658R-100000@gdi.uoregon.edu> <21b_9802201202@swimsuit.swimsuit.roskildebc.dk>
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On Fri, Feb 20, 1998 at 08:43:05AM +0100, Leif Neland wrote: > At 20 Feb 98 00:38:01 Doug White wrote regarding Re: hostid equals Ethernet > address or IP address ? > > DW> There are cases where two NICs on the same net had the same MAC. > DW> Allowing reprogramming saves the company from having to swap > DW> NICs. > > Unless somebody reprogrammed the NIC, there shouldn't exist duplicate MAC's > anywhere in the world. Aren't the manufactures supposed to give any unit its > own unique mac? > > > Leif Neland > leifn@image.dk > > --- > |Fidonet: Leif Neland 2:234/49 > |Internet: leifn@image.dk > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-questions" in the body of the message Yes, with the exception of some special cases, e.g., a bridge. They go to extreme efforts to ensure the uniqueness of MAC addresses. However, if they are also supplying utilities or documentation on how to reprogram the MAC addresses, it can certainly negate their efforts, break device drivers, cause problems with arp resolution, etc.. That said, ICs with duplicate addresses *are* produced. Sometimes buyers select the wrong supplier (I'll get them made here because it doesn't cost as much or the bill of materials listed the wrong supplier). Sometimes a contract manufacturer will receive a blank device and simply duplicate one from another board. Even network disk caching has caused the duplication of MAC addresses. Oh well, this thread has long since vectored from its original intent so it's probably time to end it before someone thinks they subscribed to hackers. ;-) -- Regards, Norman C. Rice, Jr. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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