Comment 6 for bug 1524452

If anyone wants to reproduce:

1. uvt-simplestreams-libvirt sync release=trusty arch=amd64
2. uvt-kvm create --memory 1024 --cpu 2 --disk 10 t1 release=trusty
3. uvt-kvm wait --insecure t1
4. uvt-kvm ssh --insecure t1
# inside t1 vm
5. edit /etc/network/interfaces to look like:
auto eth0
iface eth0 inet dhcp

auto eth1
iface eth1 inet static
    gateway 10.0.2.1
    address 10.0.2.100/24
    mtu 1492

auto eth1:1
iface eth1:1 inet static
    dns-nameservers 8.8.8.8
    address 10.0.2.200/24
    mtu 1492

6. sudo init 0 # shutdown vm

# back on host
7. virsh edit t1

Add another interface by injecting into the <devices> section

 <interface type='network'>
      <source network='default'/>
      <model type='virtio'/>
    </interface>

8. virsh start --console t1

You'll watch and see the 120 second block upon boot.