OpenStack虚拟机DHCP获取不到IP地址排查

版本:OpenStack Liberty Neutron DVR

 

现象:

1、在虚拟机内部不停地dhclient

2、在虚拟机所属的计算节点的物理网卡上抓包,发现该虚拟机发出的dhcp广播包

3、在虚拟机所属网络所在的NAT节点(qdhcp所在的节点)的物理网卡上抓包,同样发现了该虚拟机发出的dhcp广播包,即在bond1上抓到了包:

    Bridge br-int
        fail_mode: secure
        Port "sg-297691c4-9f"
            tag: 1
            Interface "sg-297691c4-9f"
                type: internal
        Port "tap8a1db903-07"
            tag: 2
            Interface "tap8a1db903-07"
                type: internal
        Port br-int
            Interface br-int
                type: internal
        Port "qr-8d397111-81"
            tag: 1
            Interface "qr-8d397111-81"
                type: internal
        Port int-br-vlan
            Interface int-br-vlan
                type: patch
                options: {peer=phy-br-vlan}
        Port "tap15d024ee-23"
            tag: 1
            Interface "tap15d024ee-23"
                type: internal
    Bridge br-ex
        Port br-ex
            Interface br-ex
                type: internal
        Port "qg-ab607114-19"
            Interface "qg-ab607114-19"
                type: internal
    Bridge br-vlan
        Port br-vlan
            Interface br-vlan
                type: internal
        Port phy-br-vlan
            Interface phy-br-vlan
                type: patch
                options: {peer=int-br-vlan}
        Port "bond1"
            Interface "bond1"
    ovs_version: "2.4.0"

4、但是在qdhcp的网卡tap15d024ee-23抓不到dhcp广播包,查看各个ovs bridge的流表未发现什么问题,很是奇怪

 

原因:

后来在同事的帮助下,发现这个bond1还被加到了一个linux bridge上:

brctl show
bridge name    bridge id        STP enabled    interfaces
br0        8000.1418774dd6a3    no        em1
br1        8000.90e2ba8465f2    no        bond1

 

分析:

原来这个bond1被加入到linux bridge上时,导致虽然看上去也被绑到br-vlan上,但是实际上并没有生效,因此导致上层的br-int无法收到dhcp广播包

 

解决:

将该bond1从linux bridge上解绑掉,然后重新加入到ovs bridge br-vlan上

 

posted on 2016-06-30 13:04  CasonChan  阅读(9213)  评论(0编辑  收藏

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