Switching to randomly generated hostnames

[Paul Fox]

kevin wrote:
 > On Wed, May 2, 2012 at 10:52 AM, Daniel Drake <dsd at laptop.org> wrote:
 > 
 > > On Tue, May 1, 2012 at 4:49 PM, John Gilmore <gnu at toad.com> wrote:
 > > >> Currently, XO hostnames are set on first boot in the following format:
 > > >> xo-A-B-C
 > > >> Where A, B and C are the last 3 bytes of the MAC address expressed in
 > > hex.
 > > >>
 > > >> In Nicaragua we are seeing cases where XOs have no hostname set, both
 > > >> on XO-1 and XO-1.5. On XO-1 this is presumably because libertas
 > > >> usb8388 init was never 100% reliable, and on XO-1.5 its presumably
 > > >> because the wireless card was DOA but was replaced after first boot.
 > > >
 > > > Why would we need to get it from the wireless card?  Isn't the
 > > > laptop's MAC address stored in the manufacturing data in motherboard
 > > > flash?
 > >
 > > Good point.
 > >
 > 
 > I believe I've seen cases where the mfg data doesnt match the actual real
 > MAC address.  If memory serves, it's on the older 1.5's, presumably where
 > the wireless module had been swapped out.  If that is the case, it might

you're correct on both counts:  that it may not match, and that it
probably won't matter.

paul

 > not matter, since the use case is that the old module was probably trashed
 > and so the mfg data is still as unique as it needs to be.  Also, I'm at
 > work and don't have the old 1.5's in front of me  right now, so I could be
 > mistaken and the mfg data does get auto-magically updated when the module
 > is switched.  If so, sorry for the noise.
 > 
 > >
 > > >> I propose we move to generating hostnames in the same format as before
 > > >> (xo-A-B-C), but with A, B and C assigned as random hex digits on first
 > > >> boot.
 > > >> (If people are worried about collisions, maybe we add a D digit.)
 > > >
 > > > Existing hostnames have three bytes of info (e.g. xo-12-3a-49).
 > > > Particularly if you're going to generate them at random rather than
 > > > by prior assignment like MACs, why reduce the amount of unique
 > > > information (e.g. xo-1-a-4 or xo-1-a-4-d)?  Producing three random
 > > > bytes of info for the hostname, rather than 1.5 or 2 bytes, would
 > > > reduce the chance of collisions; and has the advantage of not
 > > > changing either the size or format of the hostnames, in case
 > > > anything else is depending on it.
 > >
 > > You're right. When I wrote "hex digits" I actually meant to write "hex
 > > bytes". i.e. I was not suggesting that we reduce the amount of data,
 > > only change where it comes from.
 > >
 > > Daniel
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 > >
 > part 2     text/plain                 129
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=---------------------
 paul fox, pgf at laptop.org