Introduction

In this wiki page, we are going to show you how to setup the hardware switches for CORD Fabric.
Here we focus on Accton 6712 (32 X 40G) switches, which are the switches we use to build the CORD Pod in ON.Lab.
In principle, you could use other switch models (1G, 10G, 40G, 100G) in the fabric as long as they support the OF-DPA and ONL versions listed here.

Wire Up

Connect power cable, console port and management network.

C1. Install Open Networking Linux (ONL)

The switches are shipped with Open Networking Install Environment (ONIE) bootloader. After booting up, we should see the ONIE prompt from console.
Here we assume that the management port on the switch already has Internet access. (via DHCP)

Enter ONIE

Has no ONL or ONL 1.x installed

The way to install ONL 2.x is the same as ONL 1.x. However, if you have no ONL installed or have older version of ONL, you might find it tricky to (re)install a newer version. Here's the instruction:

1. Plug in the console cable and reboot the switch
2. (If your bootloader is grub) When you see the boot menu, select ONIE -> ONIE: Rescue
3. (If your bootloader is uboot) When you see Hit any key to stop autoboot instead of the boot menu, press any key and then enter run onie_rescue to enter ONIE rescue mode.

Has ONL 2.x installed

It would be much more easier to reboot into ONIE if you have a previously installed ONL 2. Simply run

onl-onie-boot-mode install
reboot

Available ONIE modes are: {install,rescue,uninstall,update,embed,diag,none}
This can be helpful when you are in a normal ONL and want to upgrade your system. 

Install ONL

At the ONIE prompt, we need to get and install ONL. Depending on the switch model you are using, we need to use different installers from here:

For x86 based 5712 and 6712, use ONL-2.0.0-ONL-OS-DEB8-2017-07-18.1642-40fc82b-AMD64-INSTALLED-INSTALLER

In the console, type

ONIE:/ # wget <installer-url>
ONIE:/ # sh <installer-filename>

to fetch and install the latest ONL.

We might want to configure a fixed IP address for the management interface.
First edit /etc/network/interfaces and configure ma1, which is the management interface.

auto ma1
iface ma1 inet static
address 10.128.10.128
netmask 255.255.0.0
gateway 10.128.0.1
dns-nameservers 192.168.1.1 8.8.8.8

C2. Install OF-DPA package

Please download the OFDPA 3.0 EA4 release debian package from: 

For x86 based switches (eg. Accton 5712, 6712, 7712), use https://github.com/onfsdn/atrium-docs/blob/master/16A/ONOS/builds/ofdpa_3.0.4.0%2Baccton1.0~1-1_amd64.deb

Copy the package to /mnt/onl/data

$ scp ofdpa_3.0.5.5+accton1.7-1_amd64.deb 10.128.10.128:/mnt/onl/data

Install the OF-DPA package.

# dpkg -i --force-overwrite /mnt/onl/data/ofdpa_3.0.5.5+accton1.7-1_amd64.deb

C3. (Optional) Switch Port Config

By default, all 32 ports are running in 1x40G mode. The /etc/accton/ofdpa.conf need to be modified if we want to break out 1x40G into 4x10G.

port_mode_1=4x10g    # front port 1

Restart ofdpa service after modifying the config. Please check section C4. for details about how to launch OF agent.

C4. Connect Switch to ONOS

Start OFDPA and OpenFlow agent

The way to start OFDPA 3.0 EA5 is quite different from 3.0 EA4 and below.
The OFDPA software and the Indigo agent are now a single process launched by Linux service. First of all, we need to configure /etc/ofagent/ofagent.conf

Uncomment and edit the following line:

OPT_ARGS="-t <controller_ip_1> -t <controller_ip_2> -t <controller_ip_3> -i <dpid>"

Make sure all other lines are commented.

To run it in debug mode:

OPT_ARGS="-d 2 -c 2 -c 4 -t <controller_ip_1> -t <controller_ip_2> -t <controller_ip_3> -i <dpid>"

To start the ofagent, run service ofagentd start
To stop the agent, run service ofagentd stop

More ofagentapp options can be found by running ofagentapp --help

Start OFDPA and OpenFlow agent with listen option

An optional -l parameter can be added for switch to listen on specific IP:port. The switch will listen on given IP:port and allow us to use tools like ovs-ofctl or dpctl to connect and control the switch. 

OPT_ARGS="-t <controller_ip_1> -t <controller_ip_2> -t <controller_ip_3> -i <dpid> -l <ip>:<port>"

To connect to the switch using ovs-ofctl, you can use commands such as 

ovs-ofctl -O OpenFlow13 show tcp:<ip>:<port>
ovs-ofctl -O OpenFlow13 dump-flows tcp:<ip>:<port>
ovs-ofctl -O OpenFlow13 dump-groups tcp:<ip>:<port>
ovs-ofctl -O OpenFlow13 add-flow tcp:<ip>:<port> table=60,priority=40000,eth_type=0x0800,ip_dst=55.55.55.55,actions=controller

For more command, please see ovs-ofctl --help or the post OpenvSwitch ovs-ofctl and OF-DPA

C5. Config Network Interface on the Host

We need to configure the IP address and route on the host.

1. Configure the IP address and subnet mask

   Make sure the IP address and the subnet mask on the fabric network interface of the host is consistent with the information in the Network Configuration host section. 
   For example, you can run

   ip addr add 10.0.0.1/24 dev mlx0

2. Configure the default route

   Make sure you change the default route of the host to the interface IP of the leaf switch it connects to.
   For example, you can run

   ip route add default via 10.0.0.254

   
   In the case that you want to keep default route through the management network, you need to add routes to all other subnets in the network one by one.

Verification

After the setup is completed, you should be able to ping from one host to another.

Other Useful Information

ONL Boot Mode

OFDPA 2 offers two boot mode: INSTALLED and SWI.

In INSTALLED mode, ONL mounts the root filesystem from /dev/sdb7 which is a flash drive that persists everything even during a power cycle.
In SWI mode, ONL will load the root filesystem from a read-only image (*.swi) and put the modified files in an copy-on-write overlay filesystem. The change will not be persisted during a power cycle.
The pros and cons are obvious. INSTALLED mode is more convenient while SWI mode is more error-safe.

The boot mode will be determined by which image we used install ONL. We use the installed mode in this instruction for simplicity. But we can still change it after the installation. Here's the instruction:

mount /mnt/onl/boot -o remount,rw
sed -i 's/BOOTMODE=INSTALLED/BOOTMODE=SWI/g' /mnt/onl/boot/boot-config
reboot

Persistence mechanism

INSTALLED mode already persists everything for you. This section is mainly for SWI mode.

The mechanism to persist files on the switch is different from ONL 1.x to ONL 2.x. Following are the steps required to persist a file (e.g. OFDPA package) in ONL 2.x.

1. Files put in /mnt/onl/data will be persisted automatically.
2. To install a deb package during start-up, put the deb file under /mnt/onl/data/install-debs folder and create a plain text file /mnt/onl/data/install-debs/list with all the filename of the deb (e.g. ofdpa-3.0-ea0_3.0.0.0+accton1.0-1_amd64.deb)
3. To execute some command during start-up, put the command in /mnt/onl/data/rc.boot

# set static ip and route (dhcp by default)
echo 'ip addr add 10.128.0.203/16 dev ma1' >> /mnt/onl/data/rc.boot
echo 'ip route add default via 10.128.0.1' >> /mnt/onl/data/rc.boot
# grant executable permission
chmod a+x /mnt/onl/data/rc.boot

See PersistWorkflow.md for more detail.

Build a customized ONL image

Sometimes we need to build our own ONL image from source to include some extra files. (The most common case is a modified /etc/network/interfaces)
The instruction of build process has already been well-documented in ONL repo Building.md. But you might find it a little bit tricky to inject some extra files.
To do that, you need to put the files under $ONL_ROOT/builds/any/rootfs/jessie/common/overlay/ and then run the make command again.

Useful Commands

There are some useful commands under /usr/bin/

client_cfg_purge
client_debugcomp
client_drivshell
client_flowtable_dump
client_meter_dump
client_port_table_dump
client_tunnel_dump
client_classcolortable_dump
client_debuglvl
client_event
client_grouptable_dump
client_oam_dump
client_queue_config

Recovery from a faulty ONL install

If, for some reason, the ONL install process fails, you may be brought to the grub rescue prompt upon reboot. You may or may not find system files, or even basic grub rescue commands (i.e. 'help'). There are two options for returning to a (known working) ONIE prompt.

1. Reinstaller - Accton provides a ISO for reinstalling the firmware to factory default. This can be acquired from Accton by registering for their online support, and applying for it here.
   Once you have the ISO, you can either use PXE or a live USB to boot the switch into the image.
   
   

2. Manually boot to ONIE - If the files are there, you can manually configure GRUB to load the necessary modules to boot back into ONIE.

   # This should be the partition on the ONIE partition on the AS6712. 
   # It might be hd1 or hd0. Change appropriately. 
   grub rescue> ls (hd0,gpt2)/
   ./ ../ lost+found/ onie/ grub/ grubenv
   
   # These instructions will load the kernel and ONIE initrd. 
   grub rescue> set prefix=(hd0,gpt2)/grub
   grub rescue> set root=(hd0,gpt2)
   grub rescue> insmod normal
   grub rescue> insmod linux
   grub rescue> ls /onie
   ./ ../ vmlinuz-3.2.35-onie initrd.img-3.2.35-onie tools/ grub/ grub.d/ config/
   
   # if the ",115200n8" is omitted, baud rate defaults to 9600.
   grub rescue> linux /onie/vmlinuz-3.2.35-onie console=tty0 console=ttyS1,115200n8
   grub rescue> initrd /onie/initrd.img-3.2.35-onie
   
   # The system will not boot into ONIE and you can recover or re-install from there. 
   grub rescue> boot

Once back at the ONIE prompt, you can try to install ONL by following the same steps again.

Reference

• ONL/OFDPA Installation Guide by EdgeCore Network
• OFDPA/ONL cheat sheet by Phil Huang