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Re: [LUG] Linux Training


On 14/02/17 09:50, Eion MacDonald via list wrote:

> Virtual Box.
> I find that a usual problem is getting them able to 'connect WiFi' Once
> they go home from tutor sessions.
> While Linux in VB is easy for ethernet in, some distros needs careful
> handling to set up WiFi.
>  I sometimes have to go to their home to set up Wifi.
> Then take a snapshot if possible
> I like your suggested team Viewer approach but find some folk (elderly)
> have great difficulty in allowing it, while having no problem with me
> 'fiddling' with their machine at tutor session. I think it is to do with
> 'privacy of home' thinking

Ah yes, good catch here - I spend the vast majority of my time on
workstations and servers with fixed IPs and multi-gig ethernet and
sometimes forget that a lot (most?) people are actually using laptops
these days, and usually DHCP.

There *can* be an issue here, but I've run into it before and know what
it is: I prefer to manually set my VBox machines to have bridged
interfaces rather than NAT'd ones, so they get a valid IP on the parent
subnet and are pingable from everything else on the normal network (for
example, a home without having to port forward through
the host machine to the VBox internal network. For some reason this
plays havoc with UDP ports 67+68 actually reaching the virtualized
interface when using a combination of DHCP and wifi. It varies depending
on the host OS, the network setup and DHCP server configuration (normal
home routers usually fail, Cisco or pfsense type enterprise boxes
usually work fine) as to whether it will work out of the box.

Fixes are as follows (I'm presuming the most common configuration here:
a Windows OS serving as the host with a wifi connection via DHCP):

1: Switch the guest (presumably a linux test VM) network type to NAT in
the VM settings
2: Disable DHCP on the host system, and give it a fixed IP instead
3: Disable DHCP inside the guest and give it a fixed IP instead
4: Configure the guest with a static IP once, and then put it back on to
DHCP - the router will now have registered it's MAC and will be able to
"find" it the next time around

You would have to apply the "fix" (really just a slightly bodgy work
around) once and once only for each new wifi network you want to join
the VM to, which is quite possibly why the young lad mentioned was
having so many issues with his Ubuntu VM.

Because I've not made this nearly as clear as I would have liked to, I'm
rebuilding a laptop for someone at the moment and when it's done I'll
test the vanilla setup with VBox/DHCP/wifi, refresh my memory as to
exactly what the issue was and how to work around it and report back
with proper advice instead of half-remembered work arounds.

I had completely forgotten about this to be honest, so again, good catch


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