A few day after i deploy Virt Server, something going wrong with my network.
Several client got IP from unidentified DHCP server....
After taking a few step 'old school network troubleshooting'
I finally found that my Virt server act as dhcp server.
The ip's is broadcast from this interface: virbr0
here's step to disable this interface
# virsh net-list
to view virtual network interface
then, disable it straight away.. heheh..
# virsh net-destroy default
# virsh net-undefine default
# service libvirtd restart