openstack openflow流表分析
流表表格参考1，流表内容参考2
为方便描述，加一下情况分析
主干流程
1 流表0匹配，发现是patch_int口的报文，resubmit到表2（参考1中说是表1，FIXME）
cookie=0x0, duration=11509.036s, table=0, n_packets=1059, n_bytes=116533, idle_age=740, priority=1,in_port=1 actions=resubmit(,2) //从端口1及patch-int进来的traffic会被重新执行table 2的rule
2 表2（参考1中说是表1，FIXME）发现是单播，resubmit到表20
cookie=0x0, duration=11508.939s, table=0, n_packets=5, n_bytes=390, idle_age=11500, priority=0 actions=drop cookie=0x0, duration=11508.84s, table=2, n_packets=955, n_bytes=106446, idle_age=741, priority=0,dl_dst=00:00:00:00:00:00/01:00:00:00:00:00 actions=resubmit(,20) //重新执行table 20的rule
3 表20的动作
表20是一个MAC学习表，是学习来的（参考我的上篇文章）
3.1表20匹配vlan id, 匹配目的mac地址之后，
动作包括：
3.2 清空vlan id(剥掉vlan id)
3.3 设置tunnel id
3.4 输出到对应的tunnel端口(也就是原来源mac报文的入口 FIXME）
此处表20样子类似:
table=20, vlan=0x1234/0x0ffff,dl_dst=00:50*01/01:00*00, actions=strip_vlan, tun_id=3,output:3
以上主干流程
学习过程是怎么样的？
发现是来自vxlan或gre接口的报文，处理如下
1 流表0匹配，发现是vxlan/gre_int口的报文，resubmit到表2或3
cookie=0x0, duration=2089.491s, table=0, n_packets=1082, n_bytes=115494, idle_age=741, priority=1,in_port=2 actions=resubmit(,3) //从端口2 即 gre 端口进来的traffic重新执行table 3
2 表2，3查找对应tunnel_id并加上vlan id 然后发给表10
cookie=0x0, duration=2260.307s, table=3, n_packets=1082, n_bytes=115494, idle_age=741, priority=1,tun_id=0x1 actions=mod_vlan_vid:1,resubmit(,10) //从neutron node来的traffic，打上VLAN ID 1，重新执行table 10的 rule
3 表10负责建立学习表20，然后把隧道报文发给patch_int口
cookie=0x0, duration=11508.646s, table=3, n_packets=15, n_bytes=1274, idle_age=2098, priority=0 actions=drop cookie=0x0, duration=11508.495s, table=4, n_packets=0, n_bytes=0, idle_age=11508, priority=0 actions=drop cookie=0x0, duration=11508.293s, table=10, n_packets=1082, n_bytes=115494, idle_age=741, priority=1 actions=learn(table=20,hard_timeout=300,priority=1,NXM_OF_VLAN_TCI[0..11],NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[],load:0->NXM_OF_VLAN_TCI[],load:NXM_NX_TUN_ID[]->NXM_NX_TUN_ID[],output:NXM_OF_IN_PORT[]),output:1 //学习规则 table 20，从port 1 即 patch-int发出
此后又回到主干流程。
附：流表是：（参考2）
root@compute1:/var/lib/nova# ovs-ofctl dump-flows br-tun
NXST_FLOW reply (xid=0x4):
cookie=0x0, duration=11509.036s, table=0, n_packets=1059, n_bytes=116533, idle_age=740, priority=1,in_port=1 actions=resubmit(,2) //从端口1及patch-int进来的traffic会被重新执行table 2的rule
cookie=0x0, duration=2089.491s, table=0, n_packets=1082, n_bytes=115494, idle_age=741, priority=1,in_port=2 actions=resubmit(,3) //从端口2 即 gre 端口进来的traffic重新执行table 3
cookie=0x0, duration=11508.939s, table=0, n_packets=5, n_bytes=390, idle_age=11500, priority=0 actions=drop cookie=0x0, duration=11508.84s, table=2, n_packets=955, n_bytes=106446, idle_age=741, priority=0,dl_dst=00:00:00:00:00:00/01:00:00:00:00:00 actions=resubmit(,20) //重新执行table 20的rule
cookie=0x0, duration=11508.745s, table=2, n_packets=104, n_bytes=10087, idle_age=740, priority=0,dl_dst=01:00:00:00:00:00/01:00:00:00:00:00 actions=resubmit(,22) cookie=0x0, duration=2260.307s, table=3, n_packets=1082, n_bytes=115494, idle_age=741, priority=1,tun_id=0x1 actions=mod_vlan_vid:1,resubmit(,10) //从neutron node来的traffic，打上VLAN ID 1，重新执行table 10的 rule
cookie=0x0, duration=11508.646s, table=3, n_packets=15, n_bytes=1274, idle_age=2098, priority=0 actions=drop cookie=0x0, duration=11508.495s, table=4, n_packets=0, n_bytes=0, idle_age=11508, priority=0 actions=drop cookie=0x0, duration=11508.293s, table=10, n_packets=1082, n_bytes=115494, idle_age=741, priority=1 actions=learn(table=20,hard_timeout=300,priority=1,NXM_OF_VLAN_TCI[0..11],NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[],load:0->NXM_OF_VLAN_TCI[],load:NXM_NX_TUN_ID[]->NXM_NX_TUN_ID[],output:NXM_OF_IN_PORT[]),output:1 //学习规则 table 20，从port 1 即 patch-int发出
cookie=0x0, duration=11508.093s, table=20, n_packets=0, n_bytes=0, idle_age=11508, priority=0 actions=resubmit(,22) //重新执行table 22的rule
cookie=0x0, duration=2260.372s, table=22, n_packets=77, n_bytes=7817, idle_age=740, hard_age=2089, dl_vlan=1 actions=strip_vlan,set_tunnel:0x1,output:2,output:2 //去掉VLAN ID，打上TUNNEL ID 1 即 neutron 节点的TUNNEL ID，从端口2 即 gre 端口发出
cookie=0x0, duration=11507.901s, table=22, n_packets=27, n_bytes=2270, idle_age=1664, priority=0 actions=drop
参考
1 流表表格
https://wiki.openstack.org/wiki/Ovs-flow-logic
2 流表内容
http://www.tuicool.com/articles/vQZnIvJ