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I've had some success with using ssh tunnels over a public wireless network to mimic a private wireless network. This is a very light weight approach as it only requires a few lines of code:

ssh -M -f -w0:${id} ${svraddr} ''ifconfig tun${id} ${net}1 pointopoint ${net}${id}''
sleep 3
ifconfig tun0 ${net}${id} pointopoint ${net}1

Works like a champ. The problem is that the client has to dictate the tun device index on the server. This means that each device has to be provisioned a unique static index before it can connect to the network, which is unacceptable.

It's easy enough to omit the ID and let the server assign the next available, but then I can't figure out how to retrieve the assigned value to configure the network. I tried using udev rules, but so far that hasn't gotten me anywhere.

Does anyone have any ideas on how to retrieve the server-side id for a newly created tun device?


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migrated from stackoverflow.com Sep 2 '09 at 15:14

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One other detail. All the devices use the same RSA key (at least out of the box), so the authorized_keys approach doesn't look like it will help. –  Dave Causey Aug 20 '09 at 4:33
I would leverage a web API to acquire the key outside of the connection. Since it is just an incrementing ID, it should be reasonably safe to return. –  TheJacobTaylor Aug 20 '09 at 4:52
just use OpenVPN? –  derobert Aug 20 '09 at 5:01

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