FAQ: Learn more about OpenClos

By Elevate posted 08-10-2015 20:15


What problem does OpenClos solve?

One of the most complicated tasks in building an IP Fabric is assigning all of the details such as IP addresses, BGP AS numbers, routing policy, loopback address assignments, and many other implementation details. The second largest problem is automating the creation of an IP Fabric at a large scale.


OpenClos creates and automates the implementation of an IP Fabric. All network switch configurations are built using all of the IP addressing, BGP policy, and other implementation details. OpenClos also has built-in support for zero-touch provisioning (ZTP) so that all you have to do is rack-and-stack the network switches and power them on. OpenClos will automatically load the precomputed configuration files onto each switch in the IP Fabric and start the IP Fabric.


There are many use cases in the data center that require an IP Fabric architecture. For example software-as-a-service (SaaS) or software-defined networking (SDN) is best served with an IP Fabric. One of the major design tenets of an IP Fabric is that all network switches only use Layer 3, because there's no requirement for Layer 2 between racks.


What is OpenClos?


OpenClos is a set of Python scripts and libraries that have been written to automate the creation of IP Fabrics in the data center. OpenClos has been developed as an open-source project and lives on GitHub. OpenClos takes a set of inputs that describe the shape and size of a data center and it outputs network switch configuration files and even a cabling plan.

One of the major design tenets of OpenClos is that everything should be abstracted. You can easily add new network switch devices into your IP Fabric using templates. The same template architecture can be used to add new functionality to an IP Fabric such as multicast, VTEP parameters, or any company standards such as message of the day (MOTD) or users and groups.

Feel free to check out the source code or download a copy of OpenClos on GitHub. You can find it under the Juniper organization on GitHub under the OpenClos repository:


Related Documentation




Many of the large web service companies have written software many years ago to automate the creation of IP Fabrics, but these scripts have remained private and not for public use. Juniper has created the OpenClos project to provide free and open-source tools to automate the creation of IP Fabrics in the data center. Do you have an idea or code you would like to contribute? We'd be happy to accept GitHub pull requests.