[WARNING!]SqueakMap problems

Cees de Groot cg at cdegroot.com
Tue Nov 19 22:41:33 UTC 2002


[quickly wandering off-topic, I fear...]

Bert Freudenberg <bert at isg.cs.uni-magdeburg.de> said:
>Actually libuuid supports te real UUIDs too. Why not just link in libuuid?  
>It's LGPL. (Ned: AFAIK it's not really part of e2fs, only RedHat
>packages it this way)
>
A quick 'nm' over the lib shows quite a bit of system dependencies. Which, I
fear, is the only way to generate top-notch UUID's... I don't have the source
around, but is it portable?

>MAC is guaranteed to be unique. But many machines have the same IP
>address, for example local addresses (192.xxx 10.xx etc).
>
'ifconfig <dev> hw <address>'. Used more and more with broadband providers
doing access control based on MAC address. Granted, if you pick an interface
at random and use the MAC, you stand a better chance of having something
unique then if you take the IP.

And machines *do not* have an IP address (nor a MAC address). 

>The MAC+Time+PID+Counter+Random strategy is just very robust with some
>safety-nets thrown in. Even /dev/random can be buggy (or maliciously
>manipulated), right?
>
MAC/IP+Time+PID+Counter can be proven to be universally unique, iff the IP is
unique (which should be the case for e.g. Internet servers). That's the major
difference with every scheme that throws in random numbers.

-- 
Cees de Groot               http://www.cdegroot.com     <cg at cdegroot.com>
GnuPG 1024D/E0989E8B 0016 F679 F38D 5946 4ECD  1986 F303 937F E098 9E8B
Cogito ergo evigilo



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