openstack无法创建虚拟机-提示dnsmasq问题

在使用dashboard进行创建实例时，后台nova日志报如下异常，导致虚拟机无法创建，后再次初始化nova数据库，依然如此：
2015-04-09 00:54:19.293 2304 TRACE oslo.messaging.rpc.dispatcher ProcessExecutionError: Unexpected error while running command.
2015-04-09 00:54:19.293 2304 TRACE oslo.messaging.rpc.dispatcher Command: sudo nova-rootwrap /etc/nova/rootwrap.conf env CONFIG_FILE=["/usr/share/nova/nova-dist.conf", "/etc/nova/nova.conf"] NETWORK_ID=1 dnsmasq --strict-order --bind-interfaces --conf-file= --pid-file=/var/lib/nova/networks/nova-br1.pid --listen-address=192.168.100.3 --except-interface=lo --dhcp-range=set:vmnet,192.168.100.2,static,255.255.255.0,120s --dhcp-lease-max=256 --dhcp-hostsfile=/var/lib/nova/networks/nova-br1.conf --dhcp-script=/usr/bin/nova-dhcpbridge --leasefile-ro --domain=novalocal --no-hosts --addn-hosts=/var/lib/nova/networks/nova-br1.hosts
2015-04-09 00:54:19.293 2304 TRACE oslo.messaging.rpc.dispatcher Exit code: 2
2015-04-09 00:54:19.293 2304 TRACE oslo.messaging.rpc.dispatcher Stdout: u''
2015-04-09 00:54:19.293 2304 TRACE oslo.messaging.rpc.dispatcher Stderr: u'ndnsmasq: failed to set SO_REUSE{ADDR|PORT} on DHCP socket: Protocol not availablen'