<pre>
...
- <bridge name="virbr0" />
+ <bridge name="virbr0" stp="on" delay="5"/>
<forward mode="nat" dev="eth0"/>
...</pre>
device names started with the prefix <code>vir</code>, but the name
<code>virbr0</code> is reserved for the "default" virtual network.
This element should always be provided when defining a new network.
+ Attribute <code>stp</code> specifies if Spanning Tree Protocol is
+ 'on' or 'off' (default is 'on'). Attribute <code>delay</code> sets
+ the bridge's forward delay value in seconds (default is 0).
<span class="since">Since 0.3.0</span>
</dd>
<dt><code>forward</code></dt>