[ethbridge-discuss] Re: EthBridge and OpenVPN Tun/Tap

[David Edmondson]

(We're wandering off topic a bit, but...)

* sol11x86 at adelphia.net [2007-02-01 18:04:02]
>> Anyone given some thought as to how this project might bring
>> bridging support for the OpenVPN project. That project uses the
>> TUN/TAP drivers, the latter of which doesn't exist for Solaris,
>> hence not allowing the goodness of bridging mode.
>
> The blastwave 0.7.0 version of qemu supports those tun/tap drivers
> and we could use the bridging ability provided by this module to
> allow a qemu guest on Solaris get a real IP address from an external
> DHCP server.

For the qemu bits used with Xen HVM I took a different approach, which
was to open the network device directly, configure it appropriately
and filter packets.  The code added to qemu is very small - less than
a couple of hundred lines.  It does require that qemu run with the
ability to open DLPI devices, but with HVM that is already the case.

The next step is to use Crossbow VNICs and create a VNIC that
represents the qemu emulated interface.  This shows significantly
better performance than using the bridge code.  We're using this
mechanism with Xen paravirtualised guest domains and I'll make the
very small changes necessary to use it with HVM in the near future.

dme.
-- 
David Edmondson, Sun Microsystems, http://www.dme.org