[root@hp8300 vmx]# virsh net-dumpxml default
<network>
<name>default</name>
<uuid>7c445c27-05c8-45b3-8049-4fa6b5b01778</uuid>
<forward mode='nat'/>
<bridge name='virbr0' stp='on' delay='0'/>
<mac address='52:54:00:b5:3c:54'/>
<ip address='192.168.122.1' netmask='255.255.255.0'>
<dhcp>
<range start='192.168.122.2' end='192.168.122.254'/>
</dhcp>
</ip>
</network>convert a network name to network UUID
[root@hp8300 vmx]# more /etc/libvirt/qemu/networks/default.xml
<network>
<name>default</name>
<uuid>7c445c27-05c8-45b3-8049-4fa6b5b01778</uuid>
<bridge name="virbr0" />
<mac address='52:54:00:B5:3C:54'/>
<forward/>
<ip address="192.168.122.1" netmask="255.255.255.0">
<dhcp>
<range start="192.168.122.2" end="192.168.122.254" />
</dhcp>
</ip>
</network>