Implementation

Arista EOS provides the ability to have the contents of prefix-lists and as-path access-lists retrieved dynamically from an arbitrary URL.

This feature allows the presence of the policy object and the source of its contents defined in the running-configuration, whilst omitting the contents.

The EOS SDK provides the ability to run third party extension code under the EOS process manager, in order that the extension can be configured via the EOS running-configuration, and can register callbacks against events occurring in the main event loop.

The agent is configured to periodically inspect the current running-configuration for prefix-list objects with a source that matches a well defined pattern.

For each such object, the agent will execute the necessary queries to write the entries in the prefix-list to the file system, and instruct EOS to reload their contents.

The agent does not query an IRR database server directly, but relies on the availability of an instance of RPTK to provide an easy-to-consume JSON based API.