nat_router

Router and NAT

In this example we use a router with a NAT. In particular we have:

• 2 switches
• a router connected to a NAT

configuration:

• ns1 (ip 10.0.1.1/24 dg 10.0.1.254)
• ns2 (ip 10.0.2.1/24 dg 10.0.2.254)
• ns3 (ip 10.10.1.1/24 dg 10.10.1.100)

topology

ns1 <--> Switch1
            |
            |
      (10.0.1.254/24)
            |
          Router <--> Nat (10.10.1.100) <--> ns3
            |
      (10.0.2.254/24)
            |
            |
ns2 <--> Switch2

Preparing the network namespaces

Execute the setup.sh script:

sudo ./setup.sh

Launching hover

Before deploying the router, it is necessary to launch the hover daemon. Please note to kill other instances of hover previously running.

export GOPATH=$HOME/go
sudo $GOPATH/bin/hoverd -listen 127.0.0.1:5002

Deploying the topology

The nat_router.yaml file contains the configuration script. To launch the example please execute:

export GOPATH=$HOME/go
cd $GOPATH/src/github.com/iovisor/iovisor-ovn/examples/switch
$GOPATH/bin/iovisorovnd -file nat_router.yaml -hover http://127.0.0.1:5002

Testing connectivity

In order to allow the arp tables to be correctly completed, please run arp.sh script:

sudo ./arp.sh

Now you are able to test the connectivity TCP and UDP using netcat (nc). Example:

# Launch netcat server in ns3
sudo ip netns exec ns3 nc -l 8000
# Launch netcat client in ns1
sudo ip netns exec ns1 nc 10.10.1.1 8000
# Launch netcat client in ns2
sudo ip netns exec ns2 nc 10.10.1.1 8000

Debugging

In order to see the debug output generated by the IOModule we suggest to see the result of the print on the trace_pipe.

sudo su
cd /sys/kernel/debug/tracing/
cat trace_pipe