Changes between Initial Version and Version 1 of HowTo/ConfigureOVSStaticRouteMirroringNoController

Timestamp:

06/19/17 10:14:05 (7 years ago)

Author:

joshua.fasching@raytheon.com

Comment:

--

HowTo/ConfigureOVSStaticRouteMirroringNoController

@@ +1 @@
+This tutorial demonstrates how to set up static IP traffic between two hosts
+connected to an OVS switch without running a seperate controller. This tutorial
+uses custom OpenFlow table rules.
+
+This tutorial uses the following rspec: *.xml
+
+This rspec creates a network with 3 nodes: host1, host2, host3; connected to an OVSwitch ovs.
+
+Picture of the network
+
+
+This tutorial will establish rules for allowing IP traffic to flow between host1 and host2.
+
+Later in the tutorial we will discuss how to setup the ovs switch to allow
+for host3 to observe the traffic between host1 and host2 using the Mirror feature of the ovs switch.
+This could be used for network monitoring setups.
+
+Setting up the static IP traffic
+--------------------------------
+
+Use ssh to login to the ovs node.
+
+Use this text to setup the switch
+http://groups.geni.net/geni/wiki/GENIExperimenter/Tutorials/OpenFlowRyu/DesignSetup/ 2a. Configure the Software Switch (OVS Window)
+
+We want our switch to act without a seperate controller thus setting it to operate as standalone.
+
+sudo ovs-vsctl set-fail-mode br0 standalone
+
+"Доверяй, но проверяй" {Doveryai, no proveryai} Trust but verify. You can verify your OVS settings by issuing the following:
+
+sudo ovs-vsctl show
+
+Testing the connectivity between host1, host2 and host3
+-------------------------------------------
+Initially the OVSwitch is setup to act like an L2 learning switch. We want to disable this behavior
+except for specific IP addresses
+
+sudo ovs-ofctl del-flows br0
+
+From host1
+ping -c 10  host2
+
+From host2
+ping -c 10 host1
+
+From host3
+ping -c 10 host2
+
+Each of these should be unreachable.
+
+
+Setting up the static IP flows
+------------------------------
+With the switch set up we can now setup routing between host1 and host2
+
+First we will add rules to allow the OVS switch to behave like a normal switch for IP traffic between
+the two hosts
+
+sudo ovs-ofctl add-flow br0 priority=500,ip,nw_src=10.10.1.1,nw_dst=10.10.1.2,actions=normal
+sudo ovs-ofctl add-flow br0 priority=500,ip,nw_src=10.10.1.2,nw_dst=10.10.1.1,actions=normal
+
+ARP traffic will also need to be able to flow in order for the routes to each host to be learned.
+
+sudo ovs-ofctl add-flow br0 "priority=500,arp,nw_dst=10.10.1.1 actions=normal"
+sudo ovs-ofctl add-flow br0 "priority=500,arp,nw_dst=10.10.1.2 actions=normal"
+
+The connectivity can then be tested with:
+
+From host1
+ping -c 10 host2
+
+From host2
+ping -c 10 host1
+
+From host3
+ping -c 10 host2
+
+Pings between host1 and host2 should succeed whereas pings from host3 will fail.
+
+
+Setting up mirroring of traffic from host1 and host2 to host3
+
+This is done with a single command to ovs-vsctl. It can be done
+independant of the previous steps if only mirroring is of interest
+to the user.
+
+ovs-vsctl -- set Bridge br0 mirrors=@m \
+              -- --id=@ethX get Port ethX \
+              -- --id=@ethY get Port ethY \
+              -- --id=@ethZ get Port ethZ \
+              -- --id=@m create Mirror name=mymirror select-dst-port=@ethX,@ethY select-src-port=@ethX,@ethY output-port=@ethZ
+
+Where ethX and ethY are the names of the interfaces connected to host1 and host2 on the OVS node.
+ethZ is the interface on the OVS node that connects to host3
+
+Verifying mirroring behavior
+
+To observe the mirroring behavior 3 terminal windows will need 
+to be opened.
+
+In one terminal ssh into host1 and execute
+
+nc -ul 24565
+
+In one terminal ssh into host2 and execute
+
+nc -u host1 24565
+
+
+In one terminal ssh into host3 and execute
+
+sudo tcpdump -i eth1 -vv -X
+
+In the terminal with host2 type a message and hit return
+
+A message
+
+Observe that the message is received on host1. On host3 the packet was also
+received and we can observe the message "A message" inside of the packet.