Multipath routing with Group table

ovs command

 

ovs-vsctl set Bridge 0e2bf920-f12d-49c3-b9fe-26d888becf77 protocols="OpenFlow13"
ovs-vsctl add-br br0
ovs-vsctl add-port br0 port1 -- set Interface port1 type=internal
ovs-vsctl add-port br0 port2 -- set Interface port2 type=internal
ovs-ofctl -O OpenFlow13 add-group br0 group_id=111,type=all,bucket=output:2
ovs-ofctl -O OpenFlow13 dump-groups br0
ovs-ofctl -O OpenFlow13 show br0
ovs-vsctl add-port br0 port1
ovs-vsctl add-port br0 port2
ovs-ofctl -O OpenFlow13 dump-ports br0
ovs-ofctl -O OpenFlow13 dump-groups br0
ovsdb-client dump
#### Modify the group
ovs-ofctl -O OpenFlow13 mod-group br0 group_id=111,type=all,bucket=output:1,2
ovs-ofctl -O OpenFlow13 add-flow br0 "table=0, actions=group:111"
ovs-ofctl -O OpenFlow13 del-flow br0 "table=0, actions=group:111"
ovs-ofctl -O OpenFlow13 del-flows br0 "table=0"
ovs-ofctl -O OpenFlow13 del-groups br0 group_id=111
ovs-ofctl -O OpenFlow13 add-flow br0 "table=0, actions=group:200"

 

转载于 https://www.hwchiu.com/2014-06-25-multipath-routing-with-group-table-at-mininet.html

Purpose

在Group table中，有一個類型為select，此類型的group會隨機執行底下的其中一個bucket。若我們將所有的output action都放進這個group中，則switch會將封包隨機導向不同的port，藉此達成multipath routing的功用。

 

 

Environment

使用下列的圖作為我們的網路環境，在此圖中。S1~S5都是支援OpenFlow 1.3的OpenFlow switch，左邊的Host 1則是一個Sender，會對於右邊的九個Host發送資料
picture.png

Step

  • 使用mininet搭配其script來創造網路拓墣，該script可以在此找到 group.py

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    mn --custom group.py  --topo group

  • 讓所有的創造的openvswitch都支持openflow 1.3

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    ovs-vsctl set bridge s1 protocols=OpenFlow13
    ovs-vsctl set bridge s2 protocols=OpenFlow13
    ovs-vsctl set bridge s3 protocols=OpenFlow13
    ovs-vsctl set bridge s4 protocols=OpenFlow13
    ovs-vsctl set bridge s5 protocols=OpenFlow13

  • 在S1上面加入一個group table，此group table能夠把封包給隨機導向Port 1,2,3。

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    ovs-ofctl -O OpenFlow13 add-group s1 group_id=5566,type=select,bucket=output:1,bucket=output:2,bucket=output:3

  • 在S1上面加入一個Flow entry，所有從Host1進來的封包，都去執行剛剛所創立的group table。

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    ovs-ofctl -O OpenFlow13 add-flow s1 in_port=4,actions=group:5566

picture.png

  • 由於本實驗沒有採用任何Controller，因此要手動的寫入Flow entry到其餘的Switch。

  • 在S1上面加入剩下的Flow entry，使得送回Host1的封包能夠順利抵達Host1

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    ovs-ofctl -O OpenFlow13 add-flow s1 eth_type=0x0800,ip_dst=10.0.0.1,actions=output:4
    ovs-ofctl -O OpenFlow13 add-flow s1 eth_type=0x0806,ip_dst=10.0.0.1,actions=output:4

  • 在S2、S3、S4上各加入兩條Flow entry，讓封包能夠通過

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    ovs-ofctl -O OpenFlow13 add-flow s2 in_port=1,actions=output:2
    ovs-ofctl -O OpenFlow13 add-flow s2 in_port=2,actions=output:1
    ovs-ofctl -O OpenFlow13 add-flow s3 in_port=1,actions=output:2
    ovs-ofctl -O OpenFlow13 add-flow s3 in_port=2,actions=output:1
    ovs-ofctl -O OpenFlow13 add-flow s4 in_port=1,actions=output:2
    ovs-ofctl -O OpenFlow13 add-flow s4 in_port=2,actions=output:1

  • 在S5上根據destination ip來把封包導向不同的host

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    #IP
    ovs-ofctl -O OpenFlow13 add-flow s5 eth_type=0x0800,ip_dst=10.0.0.2,actions=output:4	
    ovs-ofctl -O OpenFlow13 add-flow s5 eth_type=0x0800,ip_dst=10.0.0.3,actions=output:5
    ovs-ofctl -O OpenFlow13 add-flow s5 eth_type=0x0800,ip_dst=10.0.0.4,actions=output:6	
    ovs-ofctl -O OpenFlow13 add-flow s5 eth_type=0x0800,ip_dst=10.0.0.5,actions=output:7
    ovs-ofctl -O OpenFlow13 add-flow s5 eth_type=0x0800,ip_dst=10.0.0.6,actions=output:8
    ovs-ofctl -O OpenFlow13 add-flow s5 eth_type=0x0800,ip_dst=10.0.0.7,actions=output:9	
    ovs-ofctl -O OpenFlow13 add-flow s5 eth_type=0x0800,ip_dst=10.0.0.8,actions=output:10
    ovs-ofctl -O OpenFlow13 add-flow s5 eth_type=0x0800,ip_dst=10.0.0.9,actions=output:11
    #ARP
    ovs-ofctl -O OpenFlow13 add-flow s5 eth_type=0x0806,ip_dst=10.0.0.2,actions=output:4	
    ovs-ofctl -O OpenFlow13 add-flow s5 eth_type=0x0806,ip_dst=10.0.0.3,actions=output:5
    ovs-ofctl -O OpenFlow13 add-flow s5 eth_type=0x0806,ip_dst=10.0.0.4,actions=output:6
    ovs-ofctl -O OpenFlow13 add-flow s5 eth_type=0x0806,ip_dst=10.0.0.5,actions=output:7
    ovs-ofctl -O OpenFlow13 add-flow s5 eth_type=0x0806,ip_dst=10.0.0.6,actions=output:8
    ovs-ofctl -O OpenFlow13 add-flow s5 eth_type=0x0806,ip_dst=10.0.0.7,actions=output:9	
    ovs-ofctl -O OpenFlow13 add-flow s5 eth_type=0x0806,ip_dst=10.0.0.8,actions=output:10
    ovs-ofctl -O OpenFlow13 add-flow s5 eth_type=0x0806,ip_dst=10.0.0.9,actions=output:11

  • 由於本實驗要觀察的是Host1送過來的封包能否走不同路徑，對於送回給Host1的封包就固定於同一條路徑(S5 - S2 - S1)

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    ovs-ofctl -O OpenFlow13 add-flow s5 eth_type=0x0800,ip_dst=10.0.0.1,actions=output:1
    ovs-ofctl -O OpenFlow13 add-flow s5 eth_type=0x0806,ip_dst=10.0.0.1,actions=output:1

  • 接下來依序執行下列指令來產生網路流量

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    mininet> iperfudp 1G h1 h2
    mininet> iperfudp 1G h1 h3
    mininet> iperfudp 1G h1 h4
    mininet> iperfudp 1G h1 h5
    mininet> iperfudp 1G h1 h6
    mininet> iperfudp 1G h1 h7
    mininet> iperfudp 1G h1 h8
    mininet> iperfudp 1G h1 h9
    mininet> iperfudp 1G h1 h10

  • 接下來觀察每個switch的flow table。結果如圖

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    mininet>  sh ovs-ofctl dump-flows s2 -O OpenFlow13
    mininet>  sh ovs-ofctl dump-flows s3 -O OpenFlow13
    mininet>  sh ovs-ofctl dump-flows s4 -O OpenFlow13

picture.png

  • 在圖中可以觀察到，S2、S3、S4上面都有流量經過，證實了S1使用了group table會將不同的flow給隨機執行不同的buckets，在此範例中則是會導向不同的port。
[root@kunpeng82 devuser]# ovs-ofctl dump-groups s1
NXST_GROUP_DESC reply (xid=0x2):
 group_id=5566,type=select,bucket=bucket_id:0,actions=output:"s1-eth1",bucket=bucket_id:1,actions=output:"s1-eth2",bucket=bucket_id:2,actions=output:"s1-eth3"
[root@kunpeng82 devuser]#

 

posted on 2020-05-28 20:23  tycoon3  阅读(344)  评论(0)  编辑  收藏  举报

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