virsh net-define << 'EOF'
<network>
<name>default</name>
<forward mode='nat'/>
<bridge name='virbr0' stp='on' delay='0'/>
<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>
EOF