[libvirt] Question about virbr(dnsmasq)

Hi all. I have the question about the option of dnsmasq that libvirt sets as a default virtual network. Why does dnsmasq listen to all NICs as specified "--except-interface lo"? And, at the following conditions, the message is output to /var/log/messages. Do you know why it is output? Conditions: 1) Dnsmasq is started by libvirt. And... # ps -ef | grep dnsmasq nobody 5877 5754 0 Jul30 ? 00:00:00 /usr/sbin/dnsmasq --keep-in-foreground --strict-order --bind-interfaces --pid-file --conf-file --listen-address 192.168.122.1 --except-interface lo --dhcp-leasefile=/var/lib/libvirt/dhcp-default.leases --dhcp-range 192.168.122.2,192.168.122.254 2) chenge the network address to '0.0.0.0'. And... # ifconfig eth3 0 up 3) Dnsmasq recieves DHCPINFORM message from other DHCP servers. Message: dnsmasq[5877]: no address range available for DHCP request via eth3 Thank you Nobuhiro Itou