On Mon, 26 Jul 2004, Eble, Dan wrote:
> If many systems are booting at the same time, is seeding with the system
> time really an appropriate solution? Shouldn't some system-specific
> value also contribute to the randomization?
Yes, i agree, it would be nicer, if we could also use some
system-specific stuff for the seeding, but i don't know if there is
such data during the initialization of the random module. For example,
we may use the MAC address of a network device, but unless i am mistaken
the initialization of such network devices take place after the random
dirver init.
By the way, i made a little test with 40 computers. They were totally
equvivalent by hardware, and all of them had a synchronized system
clock. I turned them on by Wake On LAN exactly at the same time. All of
them used the kernel level ip autoconfig, all of them got their right IP
address, and i didn't even find a line of DHCPNAK in the dhcpd logfile.
Conclusion: Although using some system-specific data and the clock would
be nicer, the system time alone also does the right thing dependably.
bye,
Cus
|