20210426 Group Table

課堂資料

Group 的種類（Type）主要有`All`、`Select`、`Indirect`以及`Fast Failover`等四種，以下分別加以介紹：

All：執行所有 Action Buckets 中的動作
Select：執行一個 Action Bucket 中的動作
Indirect：執行既有定義的某個 Action Bucket 中的動作
Fast Failover：執行第一個 Live Action Bucket 中的動作

Group Table

Load Balance ( Select )
1. hash function
2. round-robin
Fault Tolerance ( Fast-Failover )
1. watch-port-2 group 2
2. watch-port-3 group 3
Mix 1 and 2

課堂練習

Group - Select

There are two paths from H1 to H2.
One is via s1-s2-s4 and the other is via s1-s3-s4.
In this test, I will show how to use the select group entry.
The path 1 or 2 will be chosen.

cd ovs-test

cd lab3

python group-select.py

xterm h1 h2

chmod +x rule.sh

./rule.sh

ovs-ofctl dump-flows -O OpenFlow13 s1

ovs-ofctl dump-groups -O OpenFlow13 s1

ovs-ofctl dump-ports -O OpenFlow13 s1

iperf -s -i 1

iperf -s -i 1 -u

iperf -c 10.0.0.2 -t 100

iperf -c 10.0.0.2 -t 100 -u -b 1M

exit

Group - Failover

There are two paths from H1 to H2.
One is via s1-s2-s4 and the other is via s1-s3-s4.
In this test, I will show how to use the fast-failover group entry.
The path will switch to path 2 (s1-s3-s4) as soon as the port of s1 to s2 is down.

cd ..

cd lab4

python group-failover.py

xterm h1 h2

設完規則以後

link s1 s2 down

link s1 s2 up

chmod +x rules.sh

./rules.sh

ovs-ofctl dump-flows -O OpenFlow13 s1

ovs-ofctl dump-groups -O OpenFlow13 s1

ovs-ofctl dump-ports -O OpenFlow13 s1

link s1 s2 up / down 後

ovs-ofctl dump-ports -O OpenFlow13 s1

ovs-ofctl dump-ports -O OpenFlow13 s1

iperf -s -i 1 -u

iperf -c 10.0.0.2 -t 100 -u -b 1M

exit

Group - Chaining

Inspired by Efficient fast recovery mechanism in Software-Defined Networks: Multipath routing approach,the following lab to show the Group Chaining feature in openvswitch version 2.5.4.

cd ..

cd lab5

python group-chaining.py

xterm h1 h2 h1 h2

chmod +x rules.sh

./rules.sh

ovs-ofctl dump-flows -O OpenFlow13 s1

ovs-ofctl dump-groups -O OpenFlow13 s1

ovs-ofctl dump-ports -O OpenFlow13 s1

ovs-ofctl mod-port s1 s1-eth2 down

ovs-ofctl dump-ports -O OpenFlow13 s1

iperf -s -i 1 -p 5555

iperf -c 10.0.0.2 -t 1000 -p 5555

iperf -s -i 1 -p 5566

iperf -c 10.0.0.2 -t 1000 -p 5566

exit

SDN / NFV

SDN：Change the Routing Path
NFV：Network Function Virtualization 網路功能虛擬化

cd ..

mkdir nfv

cd nfv

gedit nfv.py

cd nfv

python nfv.py

xterm h2 h2

h1 ping h2 -c 5

h1 curl 10.0.0.2:8080

h1 curl 10.0.0.2:80

nfv.py

#!/usr/bin/env python
from mininet.cli import CLI
from mininet.net import Mininet
from mininet.link import Link,TCLink,Intf
from mininet.node import Controller,RemoteController
 
if '__main__' == __name__:
  net = Mininet(link=TCLink)
  h1 = net.addHost('h1', ip="10.0.0.1/24", mac="00:00:00:00:00:01")
  h2 = net.addHost('h2', ip="10.0.0.2/24", mac="00:00:00:00:00:02")
  h3 = net.addHost('h3', ip="10.0.0.3/24", mac="00:00:00:00:00:03")
  s1 = net.addSwitch('s1')
  c0 = net.addController('c0', controller=RemoteController)
  net.addLink(h1, s1)
  net.addLink(h2, s1)
  net.addLink(h3, s1)
  net.build()
  c0.start()
  s1.start([c0])

  # rules for s1
  h1.cmd("arp -s 10.0.0.2 00:00:00:00:00:02")
  h1.cmd("arp -s 10.0.0.3 00:00:00:00:00:03")
  h2.cmd("arp -s 10.0.0.1 00:00:00:00:00:01")
  h2.cmd("arp -s 10.0.0.3 00:00:00:00:00:03")
  h3.cmd("arp -s 10.0.0.1 00:00:00:00:00:01")
  h3.cmd("arp -s 10.0.0.2 00:00:00:00:00:02") 
  h3.cmd("echo 1 > /proc/sys/net/ipv4/ip_forward")
  h3.cmd("iptables -A FORWARD -p tcp --destination-port 8080 -j ACCEPT")
  h3.cmd("iptables -A FORWARD -p tcp --destination-port 80 -j DROP")
  s1.cmd("ovs-ofctl add-flow s1 priority=1,in_port=1,actions=output:2")
  s1.cmd("ovs-ofctl add-flow s1 priority=1,in_port=2,actions=output:1")
  s1.cmd("ovs-ofctl add-flow s1 priority=10,ip,in_port=1,actions=mod_dl_dst=00:00:00:00:00:03,output:3")
  s1.cmd("ovs-ofctl add-flow s1 priority=10,ip,in_port=2,actions=mod_dl_dst=00:00:00:00:00:03,output:3")
  s1.cmd("ovs-ofctl add-flow s1 priority=10,ip,in_port=3,nw_dst=10.0.0.2,actions=mod_dl_dst=00:00:00:00:00:02,output:2")
  s1.cmd("ovs-ofctl add-flow s1 priority=10,ip,in_port=3,nw_dst=10.0.0.1,actions=mod_dl_dst=00:00:00:00:00:01,output:1")


  CLI(net)
  net.stop()