Should like below:
<interface type='server'>
<mac address='52:54:00:22:c9:42'/>
<source address='192.168.0.1' port='5558'/>
</interface>
...
<interface type='client'>
<mac address='52:54:00:8b:c9:51'/>
<source address='192.168.0.1' port='5558'/>
</interface>
...
<devices>
<interface type='server'>
- <mac address='52:54:00:22:c9:42'>
+ <mac address='52:54:00:22:c9:42'/>
<source address='192.168.0.1' port='5558'/>
</interface>
...
<interface type='client'>
- <mac address='52:54:00:8b:c9:51'>
+ <mac address='52:54:00:8b:c9:51'/>
<source address='192.168.0.1' port='5558'/>
</interface>
</devices>