White Box switch: three methods for network programmability (1)

White Box switch: three methods for network programmability (1)

Even the most demanding IT professional, one word will attract his attention: cost saving. When there is a white box switch in the market-that is, a kind of consumer switch hardware that is pre-installed with a third-party network operating system, network engineers generally hear or understand that this new method may save costs.

However, as the concept of network programmability becomes more and more important, cost saving is not the most important aspect of white box switches. In addition to saving money, they can also increase network automation, programmability, and flexibility. These improvements also have their practical value.

The white box switch market, including software and hardware, is expected to grow to $2018 in 0.5 billion, according to Lee Doyle, Chief Analyst of Doyle Research in Boston. However, it is still the Early Development of Software Defined Network (SDN), because the white box switch and network operating system market are still small. Doyle pointed out that, in contrast, white box Switch vendors such as Cumulus Networks and Big Switch Networks now "may only make $2 million in revenue ".

He added that there are mainly three types of companies that focus on white box switches: internet-level companies that have the resources to deploy and maintain these vswitches, more data center operators that consider the risks of green deployment, and some cloud-based companies that do not reach the Internet level. However, most enterprises and service providers are not satisfied with any network operating system. For most companies, their operating system selection ultimately depends on the technical background of the person in charge of the purchase decision.

Joe Skorupa, a distinguished analyst at Gartner, said: "service staff will choose Cumulus Networks or Pica8, while network staff will choose Big Switch or Pica8. Cumulus Networks has a white box switch for data centers. People usually use it to support SDN stack networks, but it is not SDN itself ."

The following describes three use cases for network programmability using a cell switch.

Manage vswitches like servers

DreamHost LLC is a website hosting company and cloud provider in LA. It uses the Cumulus Linux network operating system of Cumulus Networks on a white box switch to efficiently expand and manage its own open-source Multi-lease public cloud services: dreamCompute.

Jonathan LaCour, vice president of DreamHost cloud, said: "Because the Cumulus Linux network operating system is running, we regard the switch as another Linux server. We also use the same team, tools, and procedures to manage Cumulus Linux on our Linux server ."

This is very different from the legacy vswitch of DreamHost, which runs pre-installed private software and tools, IT is completely different from the Linux tool that the IT team uses to manage and monitor computing and storage devices.

"Cumulus Linux helps us change a special network environment into a less special general environment," LaCour said ."

The Cumulus white box Switch replaces the private switch interface from a large traditional switch supplier with a common Linux interface that all Linux server administrators can understand.

Running Cumulus Linux on a white box switch can help DreamHost improve the performance of the Linux platform and achieve network visibility. At the same time, its engineers can use existing Linux server management tools to automate the network. In the same way as the installation process of Linux Server automatic configuration, except for some minor updates and modifications, no additional special considerations are required, the Cumulus Linux controller automatically configures the installation settings of its white box switch to meet the network requirements of DreamHost. This network includes the customer Pod (a self-contained hardware unit that represents an available domain of DreamHost cloud) and command and control pods for management purposes, which run the Cumulus Linux and 40GbE leaf ridge architectures.

"Although network engineers can control switches through automation, CPI (command line interface), and API programming, the special feature of Cumulus Linux is that its CLI and API are exactly the same as the Linux tools used by every system engineer and cloud engineer for a long time, such as router commands and ipconfig. They do not need to learn new things at all. Everything is accelerated by hardware ."

There is no big difference between a Linux server and a switch running Cumulus Linux-the main difference is the number of ports on each device. A Linux server may only have 2 ~ Four layer-2 and layer-3 Ethernet ports are connected, while the Cumulus white box switch has 48 10 Gb ports.

DreamHost uses the DevOps tool Opscode Chef to compile servers and networks. Because each vswitch runs the Open Shortest Path First Protocol of version 2 and version 3, all network operations, such as configuration and troubleshooting, become very simple. DreamHost engineers program the Directory management and configuration of the Cumulus Linux switch based on Chef manual and tips (a set of reusable configuration instructions. Its IT team uses the Python-based tool Graphite to monitor switches.

Switches will fail, and when they fail, Cumulus Linux will allow the DreamHost network to save route data and maintain normal operation until the switch is replaced, that is, remove the faulty switch from the network, then, the remaining vswitches are used to automatically reconstruct the network structure. Then, the Controller configures a new switch and automatically adds it to the network. In this way, the average repair time can be reduced from hours to minutes.

However, like all network platforms, Cumulus Linux is not perfect.

LaCour said: "In some complex features, the network operating system still cannot compete with the traditional switch architecture. However, this has nothing to do with our situation, because we are more willing to maintain the simplicity of the underlying network and add more features missing from white box switches on the SDN stack network ."