On Fri, 14 Jul 2000, Karl J. Runge wrote:
> Do motherboards commonly have a unique ID?
Commonly? No.
Some motherboards -- generally those in name-brand, "business" computers
from the likes of Compaq, Dell, IBM, etc. -- have a serial number or such
embedded in them for property control and customer service purposes.
The "Desktop Management Interface" specification allows space for an OEM or
VAR to record a system identifier. A system serial number (the kind
typically found on a sticker on the back of the case, for example) could be
stored there. In practice, I've rarely seen this done.
Any motherboard with an onboard network interface effectively has a unique
ID (the MAC address).
> Linux has a gethostid(3c) (and on Redhat 4.2 there was even a
> /usr/bin/hostid!)
The manpage for gethostid() on my Red Hat 6.2 system leads me to believe it
is simply generated from the system's IP network address(es).
Yah. A quick check of the sources indicates that it first tried to read a
value from /var/adm/hostid. If that fails, it tries to lookup the IP address
of the hostname. If that fails, it returns zero. If it works, it returns the
(slightly obscured) IP address:
in.s_addr << 16 | in.s_addr >> 16
Real sophisticated, there.
> Maybe it is all faked on Intel, but on other arches (e.g sparc, alpha)
> perhaps it is something on the board... Anyone know?
Such "high-end" or "professional" architectures traditionally have a unique
ID embedded in the CPU or motherboard. For specifics, you'd have to consult
someone familiar with the particular hardware you're dealing with. OEM
websites are often good for this.
--
Ben Scott <[EMAIL PROTECTED]>
| "Come not between the Dragon and his wrath." |
| - William Shakespeare, _King_Lear_, I.i.124 |
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