(OK) kvm - change - virbr0 IP range (DHCP, NAT) - virsh
[root@localhost opt]# virsh net-edit default
<network>
<name>default</name>
<uuid>27a50d30-df46-497a-817d-1e630b31230e</uuid>
<forward mode='nat'/>
<bridge name='virbr0' stp='on' delay='0'/>
<mac address='52:54:00:e3:1d:37'/>
<ip address='112.26.2.254' netmask='255.255.0.0'>
<dhcp>
<range start='112.26.2.1' end='112.26.2.253'/>
</dhcp>
</ip>
</network>