Automating Cisco SD-WAN

Automating Cisco SD-WAN through Device CLI and vManage API

Introduction to Cisco SD-WAN

SD-WAN solutions reduce the costs of running enterprise networks and by leveraging a software overlay that runs over standard network transport services, including the public Internet, MPLS, and broadband. SD-WAN also introduces a software-based controller to simplify the provisioning and management of large and complex networks that are distributed across multiple locations and geographies. SD-WAN networks provide security by implementing encrypted (IPSEC-based) end-to-end tunnels to secure data in transit. Overlay networks can also extend into public cloud infrastructure accelerating and simplifying using cloud resources like SaaS services and IaaS cloud infrastructure.

The Cisco SD-WAN solution provides advanced routing, segmentation, and security capabilities for interconnecting complex enterprise networks. Through the acquisition of Viptela, Cisco has combined cloud-first network management, orchestration, and overlay network technologies with their existing enterprise routing platforms and solutions.

The Cisco SD-WAN solution uses vManage as the primary Network Management System (NMS) which provides status, health and configuration of the other components including the vSmart controllers, vBond orchestrators and the WAN Edge routers (usually referred to as cEdge for native Cisco hardware and vEdge for the legacy Viptela hardware platforms).

Automating Cisco SD-WAN - SD WAN 1

Automating Cisco SD-WAN with Gluware

Gluware does not replace vManage. Gluware can be used for numerous use-cases to automate on-top of vManage through REST-based API calls and also through direct CLI access to the WAN Edge routers. When cEdge devices are managed through vManage they still support interaction via CLI but configuration through CLI is disabled, however, through CLI, Gluware can still perform config drift, audit and show commands for ad-hoc query and state assessment. Cisco acquired Viptela in 2017 and since has been integrating their software and porting the Viptela OS features into Cisco IOS. Gluware originally supported Viptela and the vEdge devices directly when they supported configuration through “CLI mode”, now Gluware is helping customers as they concurrently run vEdge (Viptela hardware platforms) and cEdge devices (native Cisco ISR-based platforms). For Cisco native hardware they have integrated the SD-WAN feature set in what is referred to as a “universal image” with the 17.3 branch of IOS XE that supports a command to switch between IOS mode and enabling the IOS XE SD-WAN feature sets.

Use-Cases for Gluware SD-WAN Automation

Upgrading the OS and Converting to SD-WAN Mode

Customers rolling out Cisco SD-WAN have platforms already deployed, including Cisco ISR 4k series, that support the SD-WAN feature set.  These devices need to be upgraded to 17.3 or later, and then converted to SD-WAN mode so that vManage can manage them. Using Gluware OS Manager, users can automate the OS upgrade (including ROMMON if required). Once upgraded, users can execute a Gluware workflow which will convert the device from IOS XE to IOS XE SD-WAN mode including some of the basic required settings like the SD-WAN fabric. As part of the migration, Gluware can enable Cisco Plug-and-Play (which requires internet connectivity), or perform a manual bootstrap to inject the required configuration parameters upon boot-up. Gluware customers are using this process to upgrade existing sites and also upgrade greenfield sites that have been staged with an older image and must be upgraded.

Automating Feature-based Templates through vManage

One of the challenges with vManage is that it exposes every parameter available for every device model supported. This creates a lot of distraction and navigation problems for users who do not use a majority of the features. Cisco also requires that templates be built per every device model and when sites have unique features it requires another template – resulting in template sprawl. Via API, Gluware Config Modeling is able to import the full data model from vManage and then provide customization of what the user sees, including only the specific device models and features they are using in their network. Gluware also provides the ability to edit a feature once that is shared across multiple device templates. This dramatically reduces the time to configure Feature-based templates.

Automating CLI-based Templates through vManage

Using CLI templates in vManage is also challenging since the user is faced with a field to just drop in raw CLI, and all the configuration must be correct or it will error when provisioning. Every unique device model will require a new template, every unique combination of features will require another template – resulting in template sprawl. Using Gluware leverage Config Modeling which can deconstruct the CLI into snippets, or reusable feature blocks (like ACLs, port maps, services, static routes…etc.) that have been created, tested and version controlled. This can dramatically improve the usability of creating CLI templates as well as reduce user errors and improve reusability. Once CLI templates are constructed in Gluware, they can be pushed into vManage through API, and Gluware is able to interface directly with the cEdge device to perform pre-checks and validation.

Automating Per Device Variables through vManage

When performing the final step to attach a template to a device, it will also require a per device template with specific parameters, usually 20 or more. This is performed in vManage either through form fill, manually entering all the variables, or through the import of a CSV, where the variables are created and saved outside of vManage then imported.  Either of these two options create challenges. Gluware looks to simplify this process by providing the ability to dynamically fetch the required data through a workflow. The workflow will import the variables from various sources, including Gluware as a data store and API calls to vManage and other external sources. 

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