Open Stack

Hi:all    I'm testing juno version now just follow the guide of <<openstack-install-guide-yum-juno.pdf>> from docs.openstack.org.    Everything looks OK except that when VMs renew it's ip,it will experence a network disconnection about 5 seconds.It means that,when vm start renew ip from dhcp server,the connection (I ping the www.openstack.org in the vm for testing) will lost,and the ping says "transmit failed.general failure",and when it finish renewing ip(yes,it gets the correct ip again),the network will work again.
    I have googled for my issue but can not find the exactly trouble like me,and I find one improve dhcp perormence way (https://www.mirantis.com/blog/improving-dhcp-performance-openstack/) but I think it does't make sence to me ,cause I only have 5 VMs(2 windows2008,2 centos 6.5 and 1 cirros) in my testing environment with 3 HP360 G5 Servers,it's not heavy loaded.
    Does anybody meet the same trouble like me? And any advice will be appreciated!    Thanks !

walterxj
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