Messages in this thread | | | Date | Mon, 12 Jan 1998 11:47:20 -0500 | From | "Theodore Y. Ts'o" <> | Subject | Re: devfs patch v3 |
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Date: Mon, 12 Jan 1998 05:52:10 -0500 (EST) From: "Steven N. Hirsch" <shirsch@ibm.net>
> If you have an Ethernet card, (and the manufacturer of the Ethernet card > was competent about assigning Ethernet addresses --- some weren't, > unfortuantely), the guarantees on the uniqueness of UUID's is much more > than statistical, actually.
On boxes that do not have unique machine ID's (e.g. Digital Unix on Alpha), the FlexLM license manager uses the ethernet address in lieu of the serial number. Have you actually ever encountered a duplicate enet id?
Just last year, SGI sent us (MIT) 20 Indy's all with the same Ethernet address. We had a bunch of them on the same Ethernet subnet, and it was rather surprising how few things broke, although that meant tracking down the symptoms to the ultimate cause was rather tricky.
I have also heard stories of some companies (I believe, but am not sure, that 3COM was one of them) which have also, through screwups in their manufacturing process, shipped out Ethernet boards and PCMCIA cards with identical Ethernet addresses.
It's not supposed to happen, but the Real World is often different from the pretty little world which we software-types sometimes assume. :-)
- Ted
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