[olpc-nz] [Testing] Actions: OLPC QA Call with Sri Lanka's Professional Volunteers

Mikus Grinbergs mikus at bga.com
Tue Mar 9 07:18:49 EST 2010


> 7. Holt will SHIP 12 USB-to-Ethernet dongles from Boston to Sri Lanka.

I have extensive experience at using Ethernet.  Please don't hesitate to
ask me if you have questions.


In the meantime, some things to keep in mind:

 *  The XOs expect a name server to be available on that Ethernet (to
give out dynamic IPv4 addresses).  The Ethernet ought to also have an
NTP server on it.

[I myself have not yet tried running the Ethernet with IPv6 addresses.]

 *  When you first install any XO (or first-boot any new build on that
XO), do it without having the dongle plugged in at the XO.  You can plug
the Ethernet connection in once you see any Sugar screen.

What this does is assign the Ethernet device *after* the radio device
has been assigned.  It turns out Ethernet control does not work well if
'eth0' had been assigned to the Ethernet device.  [ You can check that
Ethernet is on 'eth1' in /etc/udev/rules.d/70-persistent-net.rules ]

It helps if you keep the SAME Ethernet dongle with each individual XO.
Each time you use a different dongle, Network Manager assigns a
different interface name -- that can quickly get confusing.

 *  The Network Manager could randomly step in and assign a zeroconf IP
address to a working Ethernet interface (thereby taking the previously
existing connection down).

I actually wrote a tiny batch script that I invoke manually.  It issues
the 'ifconfig' and 'route' commands to re-establish Ethernet connection.

 *  If you boot and Ethernet is not working, issue 'ifconfig' and look
for the (usually 'eth1') interface assigned to the Ethernet.  Network
Manager is what assigns that interface - so it needs to be running.  A
good way to "kick" the Ethernet connection into life (when the XO is
running but the Ethernet isn't) is to unplug the Ethernet cable from the
dongle, wait five or more seconds, then plug the cable back in again.

 *  Attempts to assign a static IPv4 Ethernet address to an XO
may/may_not work.  Tread carefully.

 *  Treat the Ethernet icon in Frame more as an indicator than as a
control over the Ethernet connection itself.  Instead:  to start
Ethernet, plug in the cable;  to stop Ethernet, pull out the cable.


mikus



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