[Battlemesh] time sychronization in wibed

[Bernd Naumann]

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On 08/08/2015 01:41 PM, Daniel Golle wrote:
> Dear testbed team,
> 
> I just stumbled into the fact that GNUnet needs at least roughly 
> synchronized time for things to work.
> 
> https://gnunet.org/bugs/view.php?id=3932
> 
> Obviously, running systems without an RTC in an isolated
> environment will not provide that luxury to software running and
> the only lesson I still remembered out of all the things I should
> have learned in the Distributed Systems course I once visited is
> that one should never rely on the "wall clock" aka. "planetary
> time" in distributed systems. However, GNUnet partially violates
> that rule and doesn't provide any internal means to synchronize
> clocks (yet).
> 
> Thus it would be nice to have at least rdate or NTP on all nodes
> on the testbed and use it to synchronize time using the management
> mesh and touch a file inside the overlay which can then be used
> after reboot to at least get a rough idea of absolute time from the
> atime/mtime of that file which should be good enough for GNUnet to
> work.
> 
> Any ideas?
> 

there is a 'special' wibed config option called 'is_gateway' which
offers your testbed an uplink. on my local setup i just set this
option on one of the nodes or build one firmware extra for that one
gateway node; then just setup NAT on my laptop for the eth0 interface
connection. i have to look how ntp is configured on wibed but i think
this setting is untouched and therefor stock. so any node can call a
online ntp server or use that one on the local machine (which runs the
controller).

- -- 
Bernd Naumann <bernd at kr217.de>

PGP:   0xA150A04F via pool.sks-keyservers.net
XMPP:  bn at weimarnetz.de

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