Bug#860368: installer: create network bridges by default?

[Daniel Pocock <daniel@pocock.pro>]

On 15/04/17 13:05, Wouter Verhelst wrote:
> On Sat, Apr 15, 2017 at 10:50:30AM +0200, Daniel Pocock wrote:
>> With libvirt, that is possible using macvtap but it is unreliable and
>> doesn't allow[3] communication between the guest and the host, only
>> between the guest and other hosts on the subnet.
>>
>> The solution is for people to configure a bridge or Open vSwitch (OVS)
>> in /etc/network/interfaces.
> 
> Actually, you can just tell virt-manager to use the "default" network,
> which is configured correctly. However, it does not come enabled out of
> the box; to fix, you can do one of two things; either run "virsh
> net-autostart default; virsh net-start default", or use the virt-manager
> UI to do the same (under Edit->Connection details->Virtual networks)
> 
> This uses NAT, and creates a virtual NIC, which therefore requires root
> access; but it works nicely IME.
> 

As you describe, the default network is an extra layer of NAT.  It
works, but not everybody wants that.

For example, when your guest is behind NAT, you can't easily connect to
it from other hosts on the network.