场景：

创建一个Virtual Switch,支持VLAN，支持MAC-Learning

包含下面四个Port：

  • P1, truck port
  • P2, VLAN 20
  • P3, P4 VLAN 30

包含五个flow table:

    Table 0: Admission control.

    Table 1: VLAN input processing.

    Table 2: Learn source MAC and VLAN for ingress port.

    Table 3: Look up learned port for destination MAC and VLAN.

    Table 4: Output processing

首先创建一个bridge

sudo ovs-vsctl add-br helloworld -- set bridge helloworld fail-mode=secure

然后我们查看这个bridge

$ sudo ovs-vsctl show

c24322e6-8453-402a-afaf-64757ef231e9

    Bridge helloworld

        fail_mode: secure

        Port helloworld

            Interface helloworld

                type: internal

    ovs_version: "2.0.1"

$ sudo ovs-ofctl show helloworld

OFPT_FEATURES_REPLY (xid=0x2): dpid:00003ad44a48c646

n_tables:254, n_buffers:256

capabilities: FLOW_STATS TABLE_STATS PORT_STATS QUEUE_STATS ARP_MATCH_IP

actions: OUTPUT SET_VLAN_VID SET_VLAN_PCP STRIP_VLAN SET_DL_SRC SET_DL_DST SET_NW_SRC SET_NW_DST SET_NW_TOS SET_TP_SRC SET_TP_DST ENQUEUE

LOCAL(helloworld): addr:3a:d4:4a:48:c6:46

     config:     0

     state:      0

     speed: 0 Mbps now, 0 Mbps max

OFPT_GET_CONFIG_REPLY (xid=0x4): frags=normal miss_send_len=0

$ sudo ovs-ofctl dump-flows helloworld

NXST_FLOW reply (xid=0x4):

如果设为fail-secure mode，则初始情况下flow table是空的，否则会有normal

$ sudo ovs-vsctl add-br helloworld1

$ sudo ovs-ofctl show helloworld1

OFPT_FEATURES_REPLY (xid=0x2): dpid:00008a2f1d184941

n_tables:254, n_buffers:256

capabilities: FLOW_STATS TABLE_STATS PORT_STATS QUEUE_STATS ARP_MATCH_IP

actions: OUTPUT SET_VLAN_VID SET_VLAN_PCP STRIP_VLAN SET_DL_SRC SET_DL_DST SET_NW_SRC SET_NW_DST SET_NW_TOS SET_TP_SRC SET_TP_DST ENQUEUE

LOCAL(helloworld1): addr:8a:2f:1d:18:49:41

     config:     0

     state:      0

     speed: 0 Mbps now, 0 Mbps max

OFPT_GET_CONFIG_REPLY (xid=0x4): frags=normal miss_send_len=0

$ sudo ovs-ofctl dump-flows helloworld1

NXST_FLOW reply (xid=0x4):

cookie=0x0, duration=31.467s, table=0, n_packets=8, n_bytes=648, idle_age=21, priority=0 actions=NORMAL

接下来，创建四个veth pair

sudo ip link add first_br type veth peer name first_if

sudo ip link add second_br type veth peer name second_if   
sudo ip link add third_br type veth peer name third_if      
sudo ip link add forth_br type veth peer name forth_if

xxx_br将是添加到bridge上的。

我们添加四个端口port

sudo ovs-vsctl add-port helloworld first_br -- set Interface first_br ofport_request=1

sudo ovs-vsctl add-port helloworld second_br -- set Interface second_br ofport_request=2

sudo ovs-vsctl add-port helloworld third_br -- set Interface third_br ofport_request=3

sudo ovs-vsctl add-port helloworld forth_br -- set Interface forth_br ofport_request=4

ofport_request是指定端口号

新添加的port都是出于DOWN的状态

$ ip addr

22: first_if: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000

    link/ether ca:d4:fd:47:a6:ce brd ff:ff:ff:ff:ff:ff

23: first_br: <BROADCAST,MULTICAST> mtu 1500 qdisc noop master ovs-system state DOWN group default qlen 1000

    link/ether f2:ac:70:72:49:61 brd ff:ff:ff:ff:ff:ff

24: second_if: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000

    link/ether 76:fa:16:61:d7:0e brd ff:ff:ff:ff:ff:ff

25: second_br: <BROADCAST,MULTICAST> mtu 1500 qdisc noop master ovs-system state DOWN group default qlen 1000

    link/ether 66:63:74:a9:0e:f2 brd ff:ff:ff:ff:ff:ff

26: third_if: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000

    link/ether 1e:6c:0e:6f:8c:cb brd ff:ff:ff:ff:ff:ff

27: third_br: <BROADCAST,MULTICAST> mtu 1500 qdisc noop master ovs-system state DOWN group default qlen 1000

    link/ether 7e:4e:87:28:33:93 brd ff:ff:ff:ff:ff:ff

28: forth_if: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000

    link/ether 9a:0d:44:fc:6b:51 brd ff:ff:ff:ff:ff:ff

29: forth_br: <BROADCAST,MULTICAST> mtu 1500 qdisc noop master ovs-system state DOWN group default qlen 1000

    link/ether ea:01:d1:6a:2a:07 brd ff:ff:ff:ff:ff:ff

30: helloworld: <BROADCAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default

    link/ether ee:04:95:bd:a3:4b brd ff:ff:ff:ff:ff:ff

    inet6 fe80::b42d:a4ff:fe49:ba75/64 scope link

       valid_lft forever preferred_lft forever

$ sudo ovs-ofctl show helloworld

OFPT_FEATURES_REPLY (xid=0x2): dpid:0000ee0495bda34b

n_tables:254, n_buffers:256

capabilities: FLOW_STATS TABLE_STATS PORT_STATS QUEUE_STATS ARP_MATCH_IP

actions: OUTPUT SET_VLAN_VID SET_VLAN_PCP STRIP_VLAN SET_DL_SRC SET_DL_DST SET_NW_SRC SET_NW_DST SET_NW_TOS SET_TP_SRC SET_TP_DST ENQUEUE

1(first_br): addr:f2:ac:70:72:49:61

     config:     PORT_DOWN

     state:      LINK_DOWN

     current:    10GB-FD COPPER

     speed: 10000 Mbps now, 0 Mbps max

2(second_br): addr:66:63:74:a9:0e:f2

     config:     PORT_DOWN

     state:      LINK_DOWN

     current:    10GB-FD COPPER

     speed: 10000 Mbps now, 0 Mbps max

3(third_br): addr:7e:4e:87:28:33:93

     config:     PORT_DOWN

     state:      LINK_DOWN

     current:    10GB-FD COPPER

     speed: 10000 Mbps now, 0 Mbps max

4(forth_br): addr:ea:01:d1:6a:2a:07

     config:     PORT_DOWN

     state:      LINK_DOWN

     current:    10GB-FD COPPER

     speed: 10000 Mbps now, 0 Mbps max

LOCAL(helloworld): addr:ee:04:95:bd:a3:4b

     config:     0

     state:      0

     speed: 0 Mbps now, 0 Mbps max

OFPT_GET_CONFIG_REPLY (xid=0x4): frags=normal miss_send_len=0

把它们设为UP

sudo ip link set first_if up

sudo ip link set first_br up

sudo ip link set second_br up    
sudo ip link set second_if up

sudo ip link set third_if up     
sudo ip link set third_br up    
sudo ip link set forth_br up        
sudo ip link set forth_if up

也可以用下面的命令

ovs-ofctl mod-port helloworld first_br up

$ sudo ip addr

22: first_if: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000

    link/ether ca:d4:fd:47:a6:ce brd ff:ff:ff:ff:ff:ff

    inet6 fe80::c8d4:fdff:fe47:a6ce/64 scope link

       valid_lft forever preferred_lft forever

23: first_br: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master ovs-system state UP group default qlen 1000

    link/ether f2:ac:70:72:49:61 brd ff:ff:ff:ff:ff:ff

    inet6 fe80::f0ac:70ff:fe72:4961/64 scope link

       valid_lft forever preferred_lft forever

24: second_if: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000

    link/ether 76:fa:16:61:d7:0e brd ff:ff:ff:ff:ff:ff

    inet6 fe80::74fa:16ff:fe61:d70e/64 scope link

       valid_lft forever preferred_lft forever

25: second_br: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master ovs-system state UP group default qlen 1000

    link/ether 66:63:74:a9:0e:f2 brd ff:ff:ff:ff:ff:ff

    inet6 fe80::6463:74ff:fea9:ef2/64 scope link

       valid_lft forever preferred_lft forever

26: third_if: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000

    link/ether 1e:6c:0e:6f:8c:cb brd ff:ff:ff:ff:ff:ff

    inet6 fe80::1c6c:eff:fe6f:8ccb/64 scope link

       valid_lft forever preferred_lft forever

27: third_br: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master ovs-system state UP group default qlen 1000

    link/ether 7e:4e:87:28:33:93 brd ff:ff:ff:ff:ff:ff

    inet6 fe80::7c4e:87ff:fe28:3393/64 scope link

       valid_lft forever preferred_lft forever

28: forth_if: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000

    link/ether 9a:0d:44:fc:6b:51 brd ff:ff:ff:ff:ff:ff

    inet6 fe80::980d:44ff:fefc:6b51/64 scope link

       valid_lft forever preferred_lft forever

29: forth_br: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master ovs-system state UP group default qlen 1000

    link/ether ea:01:d1:6a:2a:07 brd ff:ff:ff:ff:ff:ff

    inet6 fe80::e801:d1ff:fe6a:2a07/64 scope link

       valid_lft forever preferred_lft forever

30: helloworld: <BROADCAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default

    link/ether ee:04:95:bd:a3:4b brd ff:ff:ff:ff:ff:ff

    inet6 fe80::b42d:a4ff:fe49:ba75/64 scope link

       valid_lft forever preferred_lft forever

$ sudo ovs-ofctl show helloworld

OFPT_FEATURES_REPLY (xid=0x2): dpid:0000ee0495bda34b

n_tables:254, n_buffers:256

capabilities: FLOW_STATS TABLE_STATS PORT_STATS QUEUE_STATS ARP_MATCH_IP

actions: OUTPUT SET_VLAN_VID SET_VLAN_PCP STRIP_VLAN SET_DL_SRC SET_DL_DST SET_NW_SRC SET_NW_DST SET_NW_TOS SET_TP_SRC SET_TP_DST ENQUEUE

1(first_br): addr:f2:ac:70:72:49:61

     config:     0

     state:      0

     current:    10GB-FD COPPER

     speed: 10000 Mbps now, 0 Mbps max

2(second_br): addr:66:63:74:a9:0e:f2

     config:     0

     state:      0

     current:    10GB-FD COPPER

     speed: 10000 Mbps now, 0 Mbps max

3(third_br): addr:7e:4e:87:28:33:93

     config:     0

     state:      0

     current:    10GB-FD COPPER

     speed: 10000 Mbps now, 0 Mbps max

4(forth_br): addr:ea:01:d1:6a:2a:07

     config:     0

     state:      0

     current:    10GB-FD COPPER

     speed: 10000 Mbps now, 0 Mbps max

LOCAL(helloworld): addr:ee:04:95:bd:a3:4b

     config:     0

     state:      0

     speed: 0 Mbps now, 0 Mbps max

OFPT_GET_CONFIG_REPLY (xid=0x4): frags=normal miss_send_len=0

实现第一个Table 0，Admission control

包进入vswitch的时候首先进入Table 0，我们在这里可以设定规则，控制那些包可以进入，那些包不可以进入。

比如，如果source address是multicast的就不允许进入。

01:00:00:00:00:00/01:00:00:00:00:00是广播地址
00:00:00:00:00:00/01:00:00:00:00:00是单播地址
这种表示形式类似CIDR
于是我们添加下面的规则：
sudo ovs-ofctl add-flow helloworld "table=0, dl_src=01:00:00:00:00:00/01:00:00:00:00:00, actions=drop"
STP的也不接受
sudo ovs-ofctl add-flow helloworld "table=0, dl_dst=01:80:c2:00:00:00/ff:ff:ff:ff:ff:f0, actions=drop"
我们在添加最后一个flow，这个flow的priority低于default，如果上面两个不匹配，则我们进入table 1
sudo ovs-ofctl add-flow helloworld "table=0, priority=0, actions=resubmit(,1)"
我们查看一下所有的flow

$ sudo ovs-ofctl dump-flows helloworld       
NXST_FLOW reply (xid=0x4):

cookie=0x0, duration=42.162s, table=0, n_packets=0, n_bytes=0, idle_age=42, priority=0 actions=resubmit(,1)

cookie=0x0, duration=232.121s, table=0, n_packets=0, n_bytes=0, idle_age=232, dl_src=01:00:00:00:00:00/01:00:00:00:00:00 actions=drop

cookie=0x0, duration=167.636s, table=0, n_packets=0, n_bytes=0, idle_age=167, dl_dst=01:80:c2:00:00:00/ff:ff:ff:ff:ff:f0 actions=drop

测试Table 0

有个很好的工具ovs-appctl ofproto/trace

不满足条件DROP

$ sudo ovs-appctl ofproto/trace helloworld in_port=1,dl_dst=01:80:c2:00:00:05

Flow: metadata=0,in_port=1,vlan_tci=0x0000,dl_src=00:00:00:00:00:00,dl_dst=01:80:c2:00:00:05,dl_type=0x0000

Rule: table=0 cookie=0 dl_dst=01:80:c2:00:00:00/ff:ff:ff:ff:ff:f0

OpenFlow actions=drop

Final flow: unchanged

Relevant fields: skb_priority=0,in_port=1,dl_src=00:00:00:00:00:00/01:00:00:00:00:00,dl_dst=01:80:c2:00:00:00/ff:ff:ff:ff:ff:f0,dl_type=0x0000,nw_frag=no

Datapath actions: drop

满足条件RESUBMIT

$ sudo ovs-appctl ofproto/trace helloworld in_port=1,dl_dst=01:80:c2:00:00:10

Flow: metadata=0,in_port=1,vlan_tci=0x0000,dl_src=00:00:00:00:00:00,dl_dst=01:80:c2:00:00:10,dl_type=0x0000

Rule: table=0 cookie=0 priority=0

OpenFlow actions=resubmit(,1)

        Resubmitted flow: unchanged

        Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

        Resubmitted  odp: drop

        No match

Final flow: unchanged

Relevant fields: skb_priority=0,in_port=1,dl_src=00:00:00:00:00:00/01:00:00:00:00:00,dl_dst=01:80:c2:00:00:10/ff:ff:ff:ff:ff:f0,dl_type=0x0000,nw_frag=no

Datapath actions: drop

实现第二个Table 1：VLAN Input Processing

首先添加一个最低优先级的DROP的规则

sudo ovs-ofctl add-flow helloworld "table=1, priority=0, actions=drop"

对于port 1，是trunk口，无论有没有VLAN Header都接受。

sudo ovs-ofctl add-flow helloworld "table=1, priority=99, in_port=1, actions=resubmit(,2)"

对于port 2, 3, 4, 我们希望没有VLAN Tag，然后我们给打上VLAN Tag

$ sudo ovs-ofctl add-flows helloworld - <<'EOF'

table=1, priority=99, in_port=2, vlan_tci=0, actions=mod_vlan_vid:20, resubmit(,2)

table=1, priority=99, in_port=3, vlan_tci=0, actions=mod_vlan_vid:30, resubmit(,2)

table=1, priority=99, in_port=4, vlan_tci=0, actions=mod_vlan_vid:30, resubmit(,2)

EOF

$ sudo ovs-ofctl dump-flows helloworld

NXST_FLOW reply (xid=0x4):

cookie=0x0, duration=4478.582s, table=0, n_packets=0, n_bytes=0, idle_age=4478, priority=0 actions=resubmit(,1)

cookie=0x0, duration=4668.541s, table=0, n_packets=0, n_bytes=0, idle_age=4668, dl_src=01:00:00:00:00:00/01:00:00:00:00:00 actions=drop

cookie=0x0, duration=4604.056s, table=0, n_packets=0, n_bytes=0, idle_age=4604, dl_dst=01:80:c2:00:00:00/ff:ff:ff:ff:ff:f0 actions=drop

cookie=0x0, duration=89.273s, table=1, n_packets=0, n_bytes=0, idle_age=89, priority=99,in_port=2,vlan_tci=0x0000 actions=mod_vlan_vid:20,resubmit(,2)

cookie=0x0, duration=89.273s, table=1, n_packets=0, n_bytes=0, idle_age=89, priority=99,in_port=4,vlan_tci=0x0000 actions=mod_vlan_vid:30,resubmit(,2)

cookie=0x0, duration=89.273s, table=1, n_packets=0, n_bytes=0, idle_age=89, priority=99,in_port=3,vlan_tci=0x0000 actions=mod_vlan_vid:30,resubmit(,2)

cookie=0x0, duration=220.318s, table=1, n_packets=0, n_bytes=0, idle_age=220, priority=99,in_port=1 actions=resubmit(,2)

cookie=0x0, duration=298.739s, table=1, n_packets=0, n_bytes=0, idle_age=298, priority=0 actions=drop

测试一个从port 1进入，tag为5的

$ sudo ovs-appctl ofproto/trace helloworld in_port=1,vlan_tci=5

Flow: metadata=0,in_port=1,vlan_tci=0x0005,dl_src=00:00:00:00:00:00,dl_dst=00:00:00:00:00:00,dl_type=0x0000

Rule: table=0 cookie=0 priority=0

OpenFlow actions=resubmit(,1)

        Resubmitted flow: unchanged

        Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

        Resubmitted  odp: drop

        Rule: table=1 cookie=0 priority=99,in_port=1

        OpenFlow actions=resubmit(,2)

                Resubmitted flow: unchanged

                Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                Resubmitted  odp: drop

                No match

Final flow: unchanged

Relevant fields: skb_priority=0,in_port=1,dl_src=00:00:00:00:00:00/01:00:00:00:00:00,dl_dst=00:00:00:00:00:00/ff:ff:ff:ff:ff:f0,dl_type=0x0000,nw_frag=no

Datapath actions: drop

测试二，从port 2进入，没有打Tag的

$ sudo ovs-appctl ofproto/trace helloworld in_port=2

Flow: metadata=0,in_port=2,vlan_tci=0x0000,dl_src=00:00:00:00:00:00,dl_dst=00:00:00:00:00:00,dl_type=0x0000

Rule: table=0 cookie=0 priority=0

OpenFlow actions=resubmit(,1)

        Resubmitted flow: unchanged

        Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

        Resubmitted  odp: drop

        Rule: table=1 cookie=0 priority=99,in_port=2,vlan_tci=0x0000

        OpenFlow actions=mod_vlan_vid:20,resubmit(,2)

                Resubmitted flow: metadata=0,in_port=2,dl_vlan=20这里被打上了Tag,dl_vlan_pcp=0,dl_src=00:00:00:00:00:00,dl_dst=00:00:00:00:00:00,dl_type=0x0000

                Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                Resubmitted  odp: drop

                No match

Final flow: unchanged

Relevant fields: skb_priority=0,in_port=2,vlan_tci=0x0000,dl_src=00:00:00:00:00:00/01:00:00:00:00:00,dl_dst=00:00:00:00:00:00/ff:ff:ff:ff:ff:f0,dl_type=0x0000,nw_frag=no

Datapath actions: drop

测试三：从port进入，带Tag 5的

$ sudo ovs-appctl ofproto/trace helloworld in_port=2,vlan_tci=5

Flow: metadata=0,in_port=2,vlan_tci=0x0005,dl_src=00:00:00:00:00:00,dl_dst=00:00:00:00:00:00,dl_type=0x0000

Rule: table=0 cookie=0 priority=0

OpenFlow actions=resubmit(,1)

        Resubmitted flow: unchanged

        Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

        Resubmitted  odp: drop

        Rule: table=1 cookie=0 priority=0

        OpenFlow actions=drop

Final flow: unchanged

Relevant fields: skb_priority=0,in_port=2,vlan_tci=0x0005,dl_src=00:00:00:00:00:00/01:00:00:00:00:00,dl_dst=00:00:00:00:00:00/ff:ff:ff:ff:ff:f0,dl_type=0x0000,nw_frag=no

Datapath actions: drop

实现第三个Table 2: MAC, VLAN learning for ingress port

对于普通的switch，都会有这个学习的过程，当一个包到来的时候，由于包里面有MAC，VLAN Tag，以及从哪个口进来的这个信息。于是switch学习后，维护了一个表格port –> MAC –> VLAN Tag。

这样以后如果有需要发给这个MAC的包，不用ARP，switch自然之道应该发给哪个port，应该打什么VLAN Tag。

OVS也要学习这个，并维护三个之间的mapping关系。

在我们的例子中，无论是从port进来的本身就带Tag的，还是从port 2, 3, 4进来的后来被打上Tag的，都需要学习。

sudo ovs-ofctl add-flow helloworld "table=2 actions=learn(table=10, NXM_OF_VLAN_TCI[0..11], NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[], load:NXM_OF_IN_PORT[]->NXM_NX_REG0[0..15]), resubmit(,3)"

这一句比较难理解。

learn表示这是一个学习的action

table 10，这是一个MAC learning table，学习的结果会放在这个table中。

NXM_OF_VLAN_TCI这个是VLAN Tag，在MAC Learning table中，每一个entry都是仅仅对某一个VLAN来说的，不同VLAN的learning table是分开的。在学习的结果的entry中，会标出这个entry是对于哪个VLAN的。

NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[]这个的意思是当前包里面的MAC Source Address会被放在学习结果的entry里面的dl_dst里面。这是因为每个switch都是通过Ingress包来学习，某个MAC从某个port进来，switch就应该记住以后发往这个MAC的包要从这个port出去，因而MAC source address就被放在了Mac destination address里面，因为这是为发送用的。

NXM_OF_IN_PORT[]->NXM_NX_REG0将portf放入register.

一般对于学习的entry还需要有hard_timeout，这是的每个学习结果都会expire，需要重新学习。

我们再来分析一个实践中，openstack中使用openvswitch的情况，这是br-tun上的规则。

cookie=0x0, duration=802188.071s, table=10, n_packets=4885, n_bytes=347789, idle_age=730, hard_age=65534, 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

cookie=0x0, duration=802187.786s, table=20, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, priority=0 actions=resubmit(,21)

 cookie=0x0, duration=802038.514s, table=20, n_packets=1239, n_bytes=83620, idle_age=735, hard_age=65534, priority=2,dl_vlan=1,dl_dst=fa:16:3e:7e:ab:cc actions=strip_vlan,set_tunnel:0x3e9,output:2

cookie=0x0, duration=802187.653s, table=21, n_packets=17, n_bytes=1426, idle_age=65534, hard_age=65534, priority=0 actions=drop

cookie=0x0, duration=802055.878s, table=21, n_packets=40, n_bytes=1736, idle_age=65534, hard_age=65534, dl_vlan=1 actions=strip_vlan,set_tunnel:0x3e9,output:2

这里table 10是用来学习的。table 20是learning table。如果table 20是空的，也即还没有学到什么，则会通过priority=0的规则resubmit到table 21.

table 21是发送规则，将br-int上的vlan tag消除，然后打上gre tunnel的id。

上面的情况中，table 20不是空的，也即发送给dl_dst=fa:16:3e:7e:ab:cc的包不用走默认规则，直接通过table 20就发送出去了。

table 20的规则是通过table 10学习得到的，table 10是一个接受规则。最终output 1，发送给了br-int

NXM_OF_VLAN_TCI[0..11]是记录vlan tag，所以学习结果中有dl_vlan=1

NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[]是将mac source address记录，所以结果中有dl_dst=fa:16:3e:7e:ab:cc

load:0->NXM_OF_VLAN_TCI[]意思是发送出去的时候，vlan tag设为0，所以结果中有actions=strip_vlan

load:NXM_NX_TUN_ID[]->NXM_NX_TUN_ID[]意思是发出去的时候，设置tunnul id，所以结果中有set_tunnel:0x3e9

output:NXM_OF_IN_PORT[]意思是发送给哪个port，由于是从port2进来的，因而结果中有output:2

测试一：从port 1来一个vlan为20的mac为50:00:00:00:00:01的包

$ sudo ovs-appctl ofproto/trace helloworld in_port=1,vlan_tci=20,dl_src=50:00:00:00:00:01 -generate  
Flow: metadata=0,in_port=1,vlan_tci=0x0014,dl_src=50:00:00:00:00:01,dl_dst=00:00:00:00:00:00,dl_type=0x0000

Rule: table=0 cookie=0 priority=0

OpenFlow actions=resubmit(,1)

        Resubmitted flow: unchanged

        Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

        Resubmitted  odp: drop

        Rule: table=1 cookie=0 priority=99,in_port=1

        OpenFlow actions=resubmit(,2)

                Resubmitted flow: unchanged

                Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                Resubmitted  odp: drop

                Rule: table=2 cookie=0

                OpenFlow actions=learn(table=10,NXM_OF_VLAN_TCI[0..11],NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[],load:NXM_OF_IN_PORT[]->NXM_NX_REG0[0..15]),resubmit(,3)

                        Resubmitted flow: unchanged

                        Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                        Resubmitted  odp: drop

                        No match

Final flow: unchanged

Relevant fields: skb_priority=0,in_port=1,vlan_tci=0x0014/0x0fff,dl_src=50:00:00:00:00:01,dl_dst=00:00:00:00:00:00/ff:ff:ff:ff:ff:f0,dl_type=0x0000,nw_frag=no

Datapath actions: drop

$ sudo ovs-ofctl dump-flows helloworld

NXST_FLOW reply (xid=0x4):

cookie=0x0, duration=90537.25s, table=0, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, priority=0 actions=resubmit(,1)

cookie=0x0, duration=90727.209s, table=0, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, dl_src=01:00:00:00:00:00/01:00:00:00:00:00 actions=drop

cookie=0x0, duration=90662.724s, table=0, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, dl_dst=01:80:c2:00:00:00/ff:ff:ff:ff:ff:f0 actions=drop

cookie=0x0, duration=86147.941s, table=1, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, priority=99,in_port=2,vlan_tci=0x0000 actions=mod_vlan_vid:20,resubmit(,2)

cookie=0x0, duration=86147.941s, table=1, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, priority=99,in_port=4,vlan_tci=0x0000 actions=mod_vlan_vid:30,resubmit(,2)

cookie=0x0, duration=86147.941s, table=1, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, priority=99,in_port=3,vlan_tci=0x0000 actions=mod_vlan_vid:30,resubmit(,2)

cookie=0x0, duration=86278.986s, table=1, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, priority=99,in_port=1 actions=resubmit(,2)

cookie=0x0, duration=86357.407s, table=1, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, priority=0 actions=drop

cookie=0x0, duration=83587.281s, table=2, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, actions=learn(table=10,NXM_OF_VLAN_TCI[0..11],NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[],load:NXM_OF_IN_PORT[]->NXM_NX_REG0[0..15]),resubmit(,3)

 cookie=0x0, duration=31.258s, table=10, n_packets=0, n_bytes=0, idle_age=31, vlan_tci=0x0014/0x0fff,dl_dst=50:00:00:00:00:01 actions=load:0x1->NXM_NX_REG0[0..15]

table 10多了一条，vlan为20，dl_dst为50:00:00:00:00:01，发送的时候从port 1出去。

测试二：从port 2进来，被打上了vlan 20，mac为50:00:00:00:00:02

$ sudo ovs-appctl ofproto/trace helloworld in_port=2,dl_src=50:00:00:00:00:02 -generate  
Flow: metadata=0,in_port=2,vlan_tci=0x0000,dl_src=50:00:00:00:00:02,dl_dst=00:00:00:00:00:00,dl_type=0x0000

Rule: table=0 cookie=0 priority=0

OpenFlow actions=resubmit(,1)

        Resubmitted flow: unchanged

        Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

        Resubmitted  odp: drop

        Rule: table=1 cookie=0 priority=99,in_port=2,vlan_tci=0x0000

        OpenFlow actions=mod_vlan_vid:20,resubmit(,2)

                Resubmitted flow: metadata=0,in_port=2,dl_vlan=20,dl_vlan_pcp=0,dl_src=50:00:00:00:00:02,dl_dst=00:00:00:00:00:00,dl_type=0x0000

                Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                Resubmitted  odp: drop

                Rule: table=2 cookie=0

                OpenFlow actions=learn(table=10,NXM_OF_VLAN_TCI[0..11],NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[],load:NXM_OF_IN_PORT[]->NXM_NX_REG0[0..15]),resubmit(,3)

                        Resubmitted flow: unchanged

                        Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                        Resubmitted  odp: drop

                        No match

Final flow: unchanged

Relevant fields: skb_priority=0,in_port=2,vlan_tci=0x0000,dl_src=50:00:00:00:00:02,dl_dst=00:00:00:00:00:00/ff:ff:ff:ff:ff:f0,dl_type=0x0000,nw_frag=no

Datapath actions: drop

$ sudo ovs-ofctl dump-flows helloworld                                                
NXST_FLOW reply (xid=0x4):

cookie=0x0, duration=90823.14s, table=0, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, priority=0 actions=resubmit(,1)

cookie=0x0, duration=91013.099s, table=0, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, dl_src=01:00:00:00:00:00/01:00:00:00:00:00 actions=drop

cookie=0x0, duration=90948.614s, table=0, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, dl_dst=01:80:c2:00:00:00/ff:ff:ff:ff:ff:f0 actions=drop

cookie=0x0, duration=86433.831s, table=1, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, priority=99,in_port=2,vlan_tci=0x0000 actions=mod_vlan_vid:20,resubmit(,2)

cookie=0x0, duration=86433.831s, table=1, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, priority=99,in_port=4,vlan_tci=0x0000 actions=mod_vlan_vid:30,resubmit(,2)

cookie=0x0, duration=86433.831s, table=1, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, priority=99,in_port=3,vlan_tci=0x0000 actions=mod_vlan_vid:30,resubmit(,2)

cookie=0x0, duration=86564.876s, table=1, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, priority=99,in_port=1 actions=resubmit(,2)

cookie=0x0, duration=86643.297s, table=1, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, priority=0 actions=drop

cookie=0x0, duration=83873.171s, table=2, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, actions=learn(table=10,NXM_OF_VLAN_TCI[0..11],NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[],load:NXM_OF_IN_PORT[]->NXM_NX_REG0[0..15]),resubmit(,3)

 cookie=0x0, duration=4.472s, table=10, n_packets=0, n_bytes=0, idle_age=4, vlan_tci=0x0014/0x0fff,dl_dst=50:00:00:00:00:02 actions=load:0x2->NXM_NX_REG0[0..15]

cookie=0x0, duration=317.148s, table=10, n_packets=0, n_bytes=0, idle_age=317, vlan_tci=0x0014/0x0fff,dl_dst=50:00:00:00:00:01 actions=load:0x1->NXM_NX_REG0[0..15]

实现第四个table 3: Look Up Destination Port

在table 2中，vswtich通过进入的包，学习了vlanid –> mac –> port的映射后，对于要发送的包，可以根据学习到的table 10里面的内容，根据destination mac和vlan，来找到相应的port发送出去，而不用每次都flood

sudo ovs-ofctl add-flow helloworld "table=3 priority=50 actions=resubmit(,10), resubmit(,4)"

添加这条规则，首先到table 10中查找learn table entry，如果找不到则到table 4

如果包本身就是multicast的或者broadcast的，则不用去table 10里面取查找。

sudo ovs-ofctl add-flow helloworld "table=3 priority=99 dl_dst=01:00:00:00:00:00/01:00:00:00:00:00 actions=resubmit(,4)"

我们进行一项测试

$ sudo ovs-appctl ofproto/trace helloworld in_port=1,dl_vlan=20,dl_src=f0:00:00:00:00:01,dl_dst=90:00:00:00:00:01 -generate  
Flow: metadata=0,in_port=1,dl_vlan=20,dl_vlan_pcp=0,dl_src=f0:00:00:00:00:01,dl_dst=90:00:00:00:00:01,dl_type=0x0000

Rule: table=0 cookie=0 priority=0

OpenFlow actions=resubmit(,1)

        Resubmitted flow: unchanged

        Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

        Resubmitted  odp: drop

        Rule: table=1 cookie=0 priority=99,in_port=1

        OpenFlow actions=resubmit(,2)

                Resubmitted flow: unchanged

                Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                Resubmitted  odp: drop

                Rule: table=2 cookie=0

                OpenFlow actions=learn(table=10,NXM_OF_VLAN_TCI[0..11],NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[],load:NXM_OF_IN_PORT[]->NXM_NX_REG0[0..15]),resubmit(,3)

                        Resubmitted flow: unchanged

                        Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                        Resubmitted  odp: drop

                        Rule: table=3 cookie=0 priority=50

                        OpenFlow actions=resubmit(,10),resubmit(,4)

                                Resubmitted flow: unchanged

                                Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                                Resubmitted  odp: drop

                                No match

                                Resubmitted flow: unchanged

                                Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                                Resubmitted  odp: drop

                                No match

Final flow: unchanged

Relevant fields: skb_priority=0,in_port=1,vlan_tci=0x0014/0x0fff,dl_src=f0:00:00:00:00:01,dl_dst=90:00:00:00:00:01,dl_type=0x0000,nw_frag=no

Datapath actions: drop

由于目标地址f0:00:00:00:00:01没有在table 10中找到，因而到达table 4.

但是这次测试使得table 10中学习到了mac地址90:00:00:00:00:01

$ sudo ovs-ofctl dump-flows helloworld

NXST_FLOW reply (xid=0x4):

cookie=0x0, duration=91588.452s, table=0, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, priority=0 actions=resubmit(,1)

cookie=0x0, duration=91778.411s, table=0, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, dl_src=01:00:00:00:00:00/01:00:00:00:00:00 actions=drop

cookie=0x0, duration=91713.926s, table=0, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, dl_dst=01:80:c2:00:00:00/ff:ff:ff:ff:ff:f0 actions=drop

cookie=0x0, duration=87199.143s, table=1, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, priority=99,in_port=2,vlan_tci=0x0000 actions=mod_vlan_vid:20,resubmit(,2)

cookie=0x0, duration=87199.143s, table=1, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, priority=99,in_port=4,vlan_tci=0x0000 actions=mod_vlan_vid:30,resubmit(,2)

cookie=0x0, duration=87199.143s, table=1, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, priority=99,in_port=3,vlan_tci=0x0000 actions=mod_vlan_vid:30,resubmit(,2)

cookie=0x0, duration=87330.188s, table=1, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, priority=99,in_port=1 actions=resubmit(,2)

cookie=0x0, duration=87408.609s, table=1, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, priority=0 actions=drop

cookie=0x0, duration=84638.483s, table=2, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, actions=learn(table=10,NXM_OF_VLAN_TCI[0..11],NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[],load:NXM_OF_IN_PORT[]->NXM_NX_REG0[0..15]),resubmit(,3)

cookie=0x0, duration=352.841s, table=3, n_packets=0, n_bytes=0, idle_age=352, priority=50 actions=resubmit(,10),resubmit(,4)

cookie=0x0, duration=212.704s, table=3, n_packets=0, n_bytes=0, idle_age=212, priority=99,dl_dst=01:00:00:00:00:00/01:00:00:00:00:00 actions=resubmit(,4)

 cookie=0x0, duration=117.364s, table=10, n_packets=0, n_bytes=0, idle_age=117, vlan_tci=0x0014/0x0fff,dl_dst=f0:00:00:00:00:01 actions=load:0x1->NXM_NX_REG0[0..15]

cookie=0x0, duration=769.784s, table=10, n_packets=0, n_bytes=0, idle_age=769, vlan_tci=0x0014/0x0fff,dl_dst=50:00:00:00:00:02 actions=load:0x2->NXM_NX_REG0[0..15]

cookie=0x0, duration=1082.46s, table=10, n_packets=0, n_bytes=0, idle_age=1082, vlan_tci=0x0014/0x0fff,dl_dst=50:00:00:00:00:01 actions=load:0x1->NXM_NX_REG0[0..15]

下面我们进行另一个测试

$ sudo ovs-appctl ofproto/trace helloworld in_port=2,dl_src=90:00:00:00:00:01,dl_dst=f0:00:00:00:00:01 -generate  
Flow: metadata=0,in_port=2,vlan_tci=0x0000,dl_src=90:00:00:00:00:01,dl_dst=f0:00:00:00:00:01,dl_type=0x0000

Rule: table=0 cookie=0 priority=0

OpenFlow actions=resubmit(,1)

        Resubmitted flow: unchanged

        Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

        Resubmitted  odp: drop

        Rule: table=1 cookie=0 priority=99,in_port=2,vlan_tci=0x0000

        OpenFlow actions=mod_vlan_vid:20,resubmit(,2)

                Resubmitted flow: metadata=0,in_port=2,dl_vlan=20,dl_vlan_pcp=0,dl_src=90:00:00:00:00:01,dl_dst=f0:00:00:00:00:01,dl_type=0x0000

                Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                Resubmitted  odp: drop

                Rule: table=2 cookie=0

                OpenFlow actions=learn(table=10,NXM_OF_VLAN_TCI[0..11],NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[],load:NXM_OF_IN_PORT[]->NXM_NX_REG0[0..15]),resubmit(,3)

                        Resubmitted flow: unchanged

                        Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                        Resubmitted  odp: drop

                        Rule: table=3 cookie=0 priority=50

                        OpenFlow actions=resubmit(,10),resubmit(,4)

                                Resubmitted flow: unchanged

                                Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                                Resubmitted  odp: drop

                                Rule: table=10 cookie=0 vlan_tci=0x0014/0x0fff,dl_dst=f0:00:00:00:00:01

                                OpenFlow actions=load:0x1->NXM_NX_REG0[0..15]

                                Resubmitted flow: reg0=0x1,metadata=0,in_port=2,dl_vlan=20,dl_vlan_pcp=0,dl_src=90:00:00:00:00:01,dl_dst=f0:00:00:00:00:01,dl_type=0x0000

                                Resubmitted regs: reg0=0x1 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                                Resubmitted  odp: drop

                                No match

Final flow: unchanged

Relevant fields: skb_priority=0,in_port=2,vlan_tci=0x0000,dl_src=90:00:00:00:00:01,dl_dst=f0:00:00:00:00:01,dl_type=0x0000,nw_frag=no

Datapath actions: drop

因为刚才学习到了mac地址f0:00:00:00:00:01，所以这次在table 10中找到了这条记录，这次同时也学习到了mac地址90:00:00:00:00:01

下面我们再发送第一次的包

$ sudo ovs-appctl ofproto/trace helloworld in_port=1,dl_vlan=20,dl_src=f0:00:00:00:00:01,dl_dst=90:00:00:00:00:01 -generate

Flow: metadata=0,in_port=1,dl_vlan=20,dl_vlan_pcp=0,dl_src=f0:00:00:00:00:01,dl_dst=90:00:00:00:00:01,dl_type=0x0000

Rule: table=0 cookie=0 priority=0

OpenFlow actions=resubmit(,1)

        Resubmitted flow: unchanged

        Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

        Resubmitted  odp: drop

        Rule: table=1 cookie=0 priority=99,in_port=1

        OpenFlow actions=resubmit(,2)

                Resubmitted flow: unchanged

                Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                Resubmitted  odp: drop

                Rule: table=2 cookie=0

                OpenFlow actions=learn(table=10,NXM_OF_VLAN_TCI[0..11],NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[],load:NXM_OF_IN_PORT[]->NXM_NX_REG0[0..15]),resubmit(,3)

                        Resubmitted flow: unchanged

                        Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                        Resubmitted  odp: drop

                        Rule: table=3 cookie=0 priority=50

                        OpenFlow actions=resubmit(,10),resubmit(,4)

                                Resubmitted flow: unchanged

                                Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                                Resubmitted  odp: drop

                                Rule: table=10 cookie=0 vlan_tci=0x0014/0x0fff,dl_dst=90:00:00:00:00:01

                                OpenFlow actions=load:0x2->NXM_NX_REG0[0..15]

                                Resubmitted flow: reg0=0x2,metadata=0,in_port=1,dl_vlan=20,dl_vlan_pcp=0,dl_src=f0:00:00:00:00:01,dl_dst=90:00:00:00:00:01,dl_type=0x0000

                                Resubmitted regs: reg0=0x2 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                                Resubmitted  odp: drop

                                No match

Final flow: unchanged

Relevant fields: skb_priority=0,in_port=1,vlan_tci=0x0014/0x0fff,dl_src=f0:00:00:00:00:01,dl_dst=90:00:00:00:00:01,dl_type=0x0000,nw_frag=no

Datapath actions: drop

发现也在table 10中找到了记录

实现第五个table 4: Output Processing

这个时候，register 0中包含了output port，如果是0则说明是flood。

对于port 1来讲，是trunk port，所以携带的vlan tag就让他带着，从port 1出去。

sudo ovs-ofctl add-flow helloworld "table=4 reg0=1 actions=1"

对于port 2来讲，是vlan 20的，然而出去的时候，vlan tag会被抹掉，从port 2发出去

对于port 3， 4来讲，是vlan 30的，然而出去的时候，vlan tag会被抹掉，从port 3, 4出去

$ sudo ovs-ofctl add-flows helloworld - <<'EOF'  
        table=4 reg0=2 actions=strip_vlan,2

        table=4 reg0=3 actions=strip_vlan,3

        table=4 reg0=4 actions=strip_vlan,4

EOF

对于broadcast来讲，我们希望一个vlan的broadcast仅仅在这个vlan里面发送，不影响其他的vlan。

$ sudo ovs-ofctl add-flows helloworld - <<'EOF'  
        table=4 reg0=0 priority=99 dl_vlan=20 actions=1,strip_vlan,2

        table=4 reg0=0 priority=99 dl_vlan=30 actions=1,strip_vlan,3,4

        table=4 reg0=0 priority=50            actions=1

EOF

所以对于register = 0的，也即是broadcast的，属于vlan 20的，则从port 1, 2出去，属于vlan 30的，则从port 1, 3, 4出去。

$ sudo ovs-ofctl dump-flows helloworld

NXST_FLOW reply (xid=0x4):

cookie=0x0, duration=92909.119s, table=0, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, priority=0 actions=resubmit(,1)

cookie=0x0, duration=93099.078s, table=0, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, dl_src=01:00:00:00:00:00/01:00:00:00:00:00 actions=drop

cookie=0x0, duration=93034.593s, table=0, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, dl_dst=01:80:c2:00:00:00/ff:ff:ff:ff:ff:f0 actions=drop

cookie=0x0, duration=88519.81s, table=1, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, priority=99,in_port=2,vlan_tci=0x0000 actions=mod_vlan_vid:20,resubmit(,2)

cookie=0x0, duration=88519.81s, table=1, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, priority=99,in_port=4,vlan_tci=0x0000 actions=mod_vlan_vid:30,resubmit(,2)

cookie=0x0, duration=88519.81s, table=1, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, priority=99,in_port=3,vlan_tci=0x0000 actions=mod_vlan_vid:30,resubmit(,2)

cookie=0x0, duration=88650.855s, table=1, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, priority=99,in_port=1 actions=resubmit(,2)

cookie=0x0, duration=88729.276s, table=1, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, priority=0 actions=drop

cookie=0x0, duration=85959.15s, table=2, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, actions=learn(table=10,NXM_OF_VLAN_TCI[0..11],NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[],load:NXM_OF_IN_PORT[]->NXM_NX_REG0[0..15]),resubmit(,3)

cookie=0x0, duration=1673.508s, table=3, n_packets=0, n_bytes=0, idle_age=1673, priority=50 actions=resubmit(,10),resubmit(,4)

cookie=0x0, duration=1533.371s, table=3, n_packets=0, n_bytes=0, idle_age=1533, priority=99,dl_dst=01:00:00:00:00:00/01:00:00:00:00:00 actions=resubmit(,4)

cookie=0x0, duration=332.478s, table=4, n_packets=0, n_bytes=0, idle_age=332, reg0=0x3 actions=strip_vlan,output:3

cookie=0x0, duration=228.839s, table=4, n_packets=0, n_bytes=0, idle_age=228, priority=50,reg0=0x0 actions=output:1

cookie=0x0, duration=483.068s, table=4, n_packets=0, n_bytes=0, idle_age=483, reg0=0x1 actions=output:1

cookie=0x0, duration=332.478s, table=4, n_packets=0, n_bytes=0, idle_age=332, reg0=0x4 actions=strip_vlan,output:4

cookie=0x0, duration=332.478s, table=4, n_packets=0, n_bytes=0, idle_age=332, reg0=0x2 actions=strip_vlan,output:2

cookie=0x0, duration=228.84s, table=4, n_packets=0, n_bytes=0, idle_age=228, priority=99,reg0=0x0,dl_vlan=30 actions=output:1,strip_vlan,output:3,output:4

cookie=0x0, duration=228.84s, table=4, n_packets=0, n_bytes=0, idle_age=228, priority=99,reg0=0x0,dl_vlan=20 actions=output:1,strip_vlan,output:2

cookie=0x0, duration=1438.031s, table=10, n_packets=0, n_bytes=0, idle_age=1438, hard_age=1109, vlan_tci=0x0014/0x0fff,dl_dst=f0:00:00:00:00:01 actions=load:0x1->NXM_NX_REG0[0..15]

cookie=0x0, duration=2090.451s, table=10, n_packets=0, n_bytes=0, idle_age=2090, vlan_tci=0x0014/0x0fff,dl_dst=50:00:00:00:00:02 actions=load:0x2->NXM_NX_REG0[0..15]

cookie=0x0, duration=1258.881s, table=10, n_packets=0, n_bytes=0, idle_age=1258, vlan_tci=0x0014/0x0fff,dl_dst=90:00:00:00:00:01 actions=load:0x2->NXM_NX_REG0[0..15]

cookie=0x0, duration=2403.127s, table=10, n_packets=0, n_bytes=0, idle_age=2403, vlan_tci=0x0014/0x0fff,dl_dst=50:00:00:00:00:01 actions=load:0x1->NXM_NX_REG0[0..15]

首先来测试一个multicast和broadcast

如果是一个port 1来的vlan 30的broadcast

$ sudo ovs-appctl ofproto/trace helloworld in_port=1,dl_dst=ff:ff:ff:ff:ff:ff,dl_vlan=30

Flow: metadata=0,in_port=1,dl_vlan=30,dl_vlan_pcp=0,dl_src=00:00:00:00:00:00,dl_dst=ff:ff:ff:ff:ff:ff,dl_type=0x0000

Rule: table=0 cookie=0 priority=0

OpenFlow actions=resubmit(,1)

        Resubmitted flow: unchanged

        Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

        Resubmitted  odp: drop

        Rule: table=1 cookie=0 priority=99,in_port=1

        OpenFlow actions=resubmit(,2)

                Resubmitted flow: unchanged

                Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                Resubmitted  odp: drop

                Rule: table=2 cookie=0

                OpenFlow actions=learn(table=10,NXM_OF_VLAN_TCI[0..11],NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[],load:NXM_OF_IN_PORT[]->NXM_NX_REG0[0..15]),resubmit(,3)

                        Resubmitted flow: unchanged

                        Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                        Resubmitted  odp: drop

                        Rule: table=3 cookie=0 priority=99,dl_dst=01:00:00:00:00:00/01:00:00:00:00:00

                        OpenFlow actions=resubmit(,4)

                                Resubmitted flow: unchanged

                                Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                                Resubmitted  odp: drop

                                Rule: table=4 cookie=0 priority=99,reg0=0x0,dl_vlan=30

                                OpenFlow actions=output:1,strip_vlan,output:3,output:4

                                skipping output to input port

Final flow: metadata=0,in_port=1,vlan_tci=0x0000,dl_src=00:00:00:00:00:00,dl_dst=ff:ff:ff:ff:ff:ff,dl_type=0x0000

Relevant fields: skb_priority=0,in_port=1,dl_vlan=30,dl_vlan_pcp=0,dl_src=00:00:00:00:00:00,dl_dst=ff:ff:ff:ff:ff:f0/ff:ff:ff:ff:ff:f0,dl_type=0x0000,nw_frag=no

Datapath actions: pop_vlan,12,13

结果是port 1就不发送了，发送给了port 3, 4

$ sudo ovs-appctl ofproto/trace helloworld in_port=3,dl_dst=ff:ff:ff:ff:ff:ff

Flow: metadata=0,in_port=3,vlan_tci=0x0000,dl_src=00:00:00:00:00:00,dl_dst=ff:ff:ff:ff:ff:ff,dl_type=0x0000

Rule: table=0 cookie=0 priority=0

OpenFlow actions=resubmit(,1)

        Resubmitted flow: unchanged

        Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

        Resubmitted  odp: drop

        Rule: table=1 cookie=0 priority=99,in_port=3,vlan_tci=0x0000

        OpenFlow actions=mod_vlan_vid:30,resubmit(,2)

                Resubmitted flow: metadata=0,in_port=3,dl_vlan=30,dl_vlan_pcp=0,dl_src=00:00:00:00:00:00,dl_dst=ff:ff:ff:ff:ff:ff,dl_type=0x0000

                Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                Resubmitted  odp: drop

                Rule: table=2 cookie=0

                OpenFlow actions=learn(table=10,NXM_OF_VLAN_TCI[0..11],NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[],load:NXM_OF_IN_PORT[]->NXM_NX_REG0[0..15]),resubmit(,3)

                        Resubmitted flow: unchanged

                        Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                        Resubmitted  odp: drop

                        Rule: table=3 cookie=0 priority=99,dl_dst=01:00:00:00:00:00/01:00:00:00:00:00

                        OpenFlow actions=resubmit(,4)

                                Resubmitted flow: unchanged

                                Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                                Resubmitted  odp: drop

                                Rule: table=4 cookie=0 priority=99,reg0=0x0,dl_vlan=30

                                OpenFlow actions=output:1,strip_vlan,output:3,output:4

                                skipping output to input port

Final flow: metadata=0,in_port=3,vlan_tci=0x0000,dl_src=00:00:00:00:00:00,dl_dst=ff:ff:ff:ff:ff:ff,dl_type=0x0000

Relevant fields: skb_priority=0,in_port=3,vlan_tci=0x0000,dl_src=00:00:00:00:00:00,dl_dst=ff:ff:ff:ff:ff:f0/ff:ff:ff:ff:ff:f0,dl_type=0x0000,nw_frag=no

Datapath actions: push_vlan(vid=30,pcp=0),10,pop_vlan,13

接着我们测试mac learning

$ sudo ovs-appctl ofproto/trace helloworld in_port=1,dl_vlan=30,dl_src=10:00:00:00:00:01,dl_dst=20:00:00:00:00:01 -generate  
Flow: metadata=0,in_port=1,dl_vlan=30,dl_vlan_pcp=0,dl_src=10:00:00:00:00:01,dl_dst=20:00:00:00:00:01,dl_type=0x0000

Rule: table=0 cookie=0 priority=0

OpenFlow actions=resubmit(,1)

        Resubmitted flow: unchanged

        Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

        Resubmitted  odp: drop

        Rule: table=1 cookie=0 priority=99,in_port=1

        OpenFlow actions=resubmit(,2)

                Resubmitted flow: unchanged

                Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                Resubmitted  odp: drop

                Rule: table=2 cookie=0

                OpenFlow actions=learn(table=10,NXM_OF_VLAN_TCI[0..11],NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[],load:NXM_OF_IN_PORT[]->NXM_NX_REG0[0..15]),resubmit(,3)

                        Resubmitted flow: unchanged

                        Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                        Resubmitted  odp: drop

                        Rule: table=3 cookie=0 priority=50

                        OpenFlow actions=resubmit(,10),resubmit(,4)

                                Resubmitted flow: unchanged

                                Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                                Resubmitted  odp: drop

                                No match

                                Resubmitted flow: unchanged

                                Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                                Resubmitted  odp: drop

                                Rule: table=4 cookie=0 priority=99,reg0=0x0,dl_vlan=30

                                OpenFlow actions=output:1,strip_vlan,output:3,output:4

                                skipping output to input port

Final flow: metadata=0,in_port=1,vlan_tci=0x0000,dl_src=10:00:00:00:00:01,dl_dst=20:00:00:00:00:01,dl_type=0x0000

Relevant fields: skb_priority=0,in_port=1,dl_vlan=30,dl_vlan_pcp=0,dl_src=10:00:00:00:00:01,dl_dst=20:00:00:00:00:01,dl_type=0x0000,nw_frag=no

Datapath actions: pop_vlan,12,13

由于这两个地址没有出现过，则除了进行学习以外，广播发送给port 3，4

$ sudo ovs-appctl ofproto/trace helloworld in_port=4,dl_src=20:00:00:00:00:01,dl_dst=10:00:00:00:00:01 -generate  
Flow: metadata=0,in_port=4,vlan_tci=0x0000,dl_src=20:00:00:00:00:01,dl_dst=10:00:00:00:00:01,dl_type=0x0000

Rule: table=0 cookie=0 priority=0

OpenFlow actions=resubmit(,1)

        Resubmitted flow: unchanged

        Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

        Resubmitted  odp: drop

        Rule: table=1 cookie=0 priority=99,in_port=4,vlan_tci=0x0000

        OpenFlow actions=mod_vlan_vid:30,resubmit(,2)

                Resubmitted flow: metadata=0,in_port=4,dl_vlan=30,dl_vlan_pcp=0,dl_src=20:00:00:00:00:01,dl_dst=10:00:00:00:00:01,dl_type=0x0000

                Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                Resubmitted  odp: drop

                Rule: table=2 cookie=0

                OpenFlow actions=learn(table=10,NXM_OF_VLAN_TCI[0..11],NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[],load:NXM_OF_IN_PORT[]->NXM_NX_REG0[0..15]),resubmit(,3)

                        Resubmitted flow: unchanged

                        Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                        Resubmitted  odp: drop

                        Rule: table=3 cookie=0 priority=50

                        OpenFlow actions=resubmit(,10),resubmit(,4)

                                Resubmitted flow: unchanged

                                Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                                Resubmitted  odp: drop

                                Rule: table=10 cookie=0 vlan_tci=0x001e/0x0fff,dl_dst=10:00:00:00:00:01

                                OpenFlow actions=load:0x1->NXM_NX_REG0[0..15]

                                Resubmitted flow: reg0=0x1,metadata=0,in_port=4,dl_vlan=30,dl_vlan_pcp=0,dl_src=20:00:00:00:00:01,dl_dst=10:00:00:00:00:01,dl_type=0x0000

                                Resubmitted regs: reg0=0x1 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                                Resubmitted  odp: drop

                                Rule: table=4 cookie=0 reg0=0x1

                                OpenFlow actions=output:1

Final flow: unchanged

Relevant fields: skb_priority=0,in_port=4,vlan_tci=0x0000,dl_src=20:00:00:00:00:01,dl_dst=10:00:00:00:00:01,dl_type=0x0000,nw_frag=no

Datapath actions: push_vlan(vid=30,pcp=0),10

回复的时候，由于学习过了，则仅仅从port 1发送出去。

$ sudo ovs-appctl ofproto/trace helloworld in_port=1,dl_vlan=30,dl_src=10:00:00:00:00:01,dl_dst=20:00:00:00:00:01 -generate

Flow: metadata=0,in_port=1,dl_vlan=30,dl_vlan_pcp=0,dl_src=10:00:00:00:00:01,dl_dst=20:00:00:00:00:01,dl_type=0x0000

Rule: table=0 cookie=0 priority=0

OpenFlow actions=resubmit(,1)

        Resubmitted flow: unchanged

        Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

        Resubmitted  odp: drop

        Rule: table=1 cookie=0 priority=99,in_port=1

        OpenFlow actions=resubmit(,2)

                Resubmitted flow: unchanged

                Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                Resubmitted  odp: drop

                Rule: table=2 cookie=0

                OpenFlow actions=learn(table=10,NXM_OF_VLAN_TCI[0..11],NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[],load:NXM_OF_IN_PORT[]->NXM_NX_REG0[0..15]),resubmit(,3)

                        Resubmitted flow: unchanged

                        Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                        Resubmitted  odp: drop

                        Rule: table=3 cookie=0 priority=50

                        OpenFlow actions=resubmit(,10),resubmit(,4)

                                Resubmitted flow: unchanged

                                Resubmitted regs: reg0=0x0 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                                Resubmitted  odp: drop

                                Rule: table=10 cookie=0 vlan_tci=0x001e/0x0fff,dl_dst=20:00:00:00:00:01

                                OpenFlow actions=load:0x4->NXM_NX_REG0[0..15]

                                Resubmitted flow: reg0=0x4,metadata=0,in_port=1,dl_vlan=30,dl_vlan_pcp=0,dl_src=10:00:00:00:00:01,dl_dst=20:00:00:00:00:01,dl_type=0x0000

                                Resubmitted regs: reg0=0x4 reg1=0x0 reg2=0x0 reg3=0x0 reg4=0x0 reg5=0x0 reg6=0x0 reg7=0x0

                                Resubmitted  odp: drop

                                Rule: table=4 cookie=0 reg0=0x4

                                OpenFlow actions=strip_vlan,output:4

Final flow: reg0=0x4,metadata=0,in_port=1,vlan_tci=0x0000,dl_src=10:00:00:00:00:01,dl_dst=20:00:00:00:00:01,dl_type=0x0000

Relevant fields: skb_priority=0,in_port=1,dl_vlan=30,dl_vlan_pcp=0,dl_src=10:00:00:00:00:01,dl_dst=20:00:00:00:00:01,dl_type=0x0000,nw_frag=no

Datapath actions: pop_vlan,13

由于在回复中进行了学习，因而发送的时候，仅仅发送port 4

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