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Test Lab Setup

The basic Test Lab Setup is designed to test ~10 devices at a time using a physical network switch. Additionally, it is the minimum setup to test switch-specific functionality such as PoE or port flapping. Although hooked together through one switch, dynamic network configuration is used to control dataflow in the system, following the outline in the device specs docs: by default, all devices are completely sequestered and tested as if they were the only one on the switch.

Architecture

           Internet
              |
              |
       +--------------+
       |              |
       |  Controller  |
       |              |
       +--------------+
         |    |    |       C = Control-plane network
         |C   |D   |(X)    D = Data-plan network
         |    |    |       X = eXtra network(s)
       +--------------+
       |              |
       |    Switch    |
       |              |
       +--------------+
          |        |
          |        |
       +-----+  +-----+
       |     |  |     |
       | DUT |  | DUT |  DUT = Device Under Test
       |     |  |     |
       +-----+  +-----+

Components

There are three main components:

  1. Controller runs DAQ and FAUCET. This should be any resonably common Debian distribution (Ubuntu ok), and nearly be anything such as a standard laptop or desktop tower. Production grade systems would be something akin to a Dell R230.
  2. Switch needs to be an OpenFlow/FAUCET compatible switch, as outlined in the FAUCET Hardware Switch documentation. For a general purpose setup any of the enterprise-grade switches should suffice, although specific switches might be more appropriate depending on the exact objectives of the lab.
  3. DUT is whatever device is intended for testing. For diagnostics, it is possible to loop back, using a physical cable, a switch port to another network adapter on the controller machine.

Connections

There are several (minimum two) network connections (ethernet cables) required between the switch and controller machines. A standard USB-dongle Ethernet adapter should be sufficient for each.

  1. Control plane, which supports the OpenFlow controller connection between switch and controller host. The port used for this is defined as part of the vendor-specific switch setup (see below).
  2. Data plane connection, which provides for all data access for the devices. Internet access for the devices will be filtered/proxied through the controller host. The port used for this is defined by the sec_port config (see below).
  3. eXtra devices, also known as faux devices (not required), can be used to run a simulated device on the controller host.

Extra Network Connections

  • To create eXtra/faux devices, use cmd/faux :[interface name], ie cmd/faux :eth1.
  • At least 1 eXtra is useful for diagnosing switch configuration problems.
  • 3 or more eXtra are recommended for a full test lab setup because it allows running core FAUCET switch tests.
  • More faux device configurations

Configuration

Configuring the test lab switch requires a few separate pieces of setup:

  1. The FAUCET Vendor-Specific Documentation for the specific switch used in any setup, including the necessary OpenFlow controller configuration (such as the port used for the control plane uplink).
  2. System configuration of the controller host. See config/system/ext.yaml for an example configuration for an external physical switch. All the following should be under the switch_setup dictionary:
    • of_dpid: Data plane ID for the connected physical switch.
    • ctrl_intf: Interface name of the control-plane network.
    • data_intf: Interface name of the data-plane network.
    • lo_port: Controller OpenFlow port (defaults to 6653).
    • lo_addr: Controller control plane IP address (and subnet).
    • ip_addr: External switch IP address (used to verify the connection).
    • uplink_port: Port of secondary (external) switch for the data-plane uplink (defaults to 7).
    • model: Currently supporting the following switch model
      • FAUX_SWITCH
      • ALLIED_TELESIS_X230
      • CISCO_9300
    • username: switch login username
    • password: switch login password

Troubleshooting

Basic network connection

The bin/physical_sec script will setup and test the basic connection to the external physical switch:

~/daq$ bin/physical_sec
Loading config from local/system.conf
Configuring control interface enxb49cdff33ad9 at 192.168.1.10/16
enxb49cdff33ad9: flags=4163  mtu 1500
        inet 192.168.1.10  netmask 255.255.0.0  broadcast 0.0.0.0
        ether b4:9c:df:f3:3a:d9  txqueuelen 1000  (Ethernet)
…

enx645aedf345fa: flags=4163  mtu 1500
        ether 64:5a:ed:f3:45:fa  txqueuelen 1000  (Ethernet)
…

Checking external connection to 192.168.1.2
PING 192.168.1.2 (192.168.1.2) 56(84) bytes of data.
64 bytes from 192.168.1.2: icmp_seq=1 ttl=64 time=3.38 ms

--- 192.168.1.2 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 3.382/3.382/3.382/0.000 ms

DAQ autoclean ip link set down dev enxb49cdff33ad9
Done with physical switch configuration.

Control Plane Interface Link

Looking at the control plane network interface can give some diagnostics about the switch setup. Using tcpdump -ni {ext_ctrl} should show the switch ext_addr address (192.168.1.2), the expected ext_ofip controller address (192.168.1.10) and ext_ofpt configured port (6653). (It's not easy to tell if the controller subnet is misconfigured.)

~/daq$ sudo tcpdump -ni enxb49cdff33ad9
…
11:30:47.739506 IP 192.168.1.2.37422 > 192.168.1.10.6653: Flags [S], seq 2153185008, win 29200, options [mss 1460,sackOK,TS val 38338000 ecr 0,nop,wscale 7], length 0
…

If there's a string of unfulfilled ARP requests, then it likely means the ext_ofip is configured incorrectly.

~/daq$ sudo tcpdump -ni enxb49cdff33ad9
…
11:34:04.739266 ARP, Request who-has 192.168.1.10 tell 192.168.1.2, length 46
11:34:08.738730 ARP, Request who-has 192.168.1.10 tell 192.168.1.2, length 46
11:34:09.738947 ARP, Request who-has 192.168.1.10 tell 192.168.1.2, length 46
…

Determining Data Plane ID.

The message below, in inst/faucet.log, indicates that a switch is trying to connect to faucet, but ext_dpid is configured wrong: simply copy/paste the hex dipd (0x1aeb960541) from inst/faucet.log into local/system.conf.

~/daq$ tail -f inst/faucet.log
…
Nov 20 23:23:56 faucet ERROR    : unknown datapath DPID 115621627201 (0x1aeb960541)

Be careful that the error doesn't come from a locally configured OVS instance. Check the output of ovs-vsctl show to make sure the wrong virtual bridge isn't running and confusing the logs. When DAQ is running configured for a physical switch, there should only be one Bridge named pri shown: if there's another (typically named sec) bridge shown, then it means the system still thinks it's running with a non-physical switch (missing the ext_intf setting).

~/daq$ sudo ovs-vsctl show | fgrep Bridge
    Bridge pri
~/daq$