Facebook Open Switching System Software for controlling network switches.
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Allwyn Carvalho and facebook-github-bot wedge_agent config: static route deletes do not take effect
While working on D6649378, we noticed a bug in the implementation of
applyConfig().  If a static route is deleted in the config, upon a warm
boot, this deletion is not taking effect.  In other words, when wedge_agent
comes up, the deleted static route is still in the route table.

Upon investigation, the bug is the way we apply static config.  We rely on
"prevCfg" to tell us what we had applied before in order to delete stale
routes.  However, in the case of warm boot there is no prevCfg, and we
cannot reconcile stale config.

The solution is to effectively "sync" all static routes, the way we do it
for BGP. I.e., delete all existing routes and add all new routes.

Differential Revision: D8219728

fbshipit-source-id: bc92e8c263541e55cef7b16111a7e3402da86eda
Latest commit 9e321df Jul 20, 2018


Facebook Open Switching System (FBOSS)

FBOSS is Facebook's software stack for controlling and managing network switches.


FBOSS consists of a number of user-space applications, libraries, and utilities.

The initial open source release of FBOSS consists primarily of the agent daemon, but we are working on releasing additional pieces and functionality as well.

Agent Daemon

One of the central pieces of FBOSS is the agent daemon, which runs on each switch, and controls the hardware forwarding ASIC. The agent daemon sends forwarding information to the hardware, and implements some control plane protocols such as ARP and NDP. The agent provides thrift APIs for managing routes, to allow external routing control processes to get their routing information programmed into the hardware forwarding tables.

The code for the agent can be found in fboss/agent

The agent requires a JSON configuration file to specify its port and VLAN configuration. Some sample configuration files can be found under fboss/agent/configs. These files are not really intended for human consumption--at Facebook we have tooling that generates these files for us.

Routing Daemon

The FBOSS agent manages the forwarding tables in the hardware ASIC, but it needs to be informed of the current routes via thrift APIs.

Our initial open source release does not yet contain a routing protocol daemon capable of talking to the agent (UPDATE: checkout Netlink Manager). The routing protocol daemon we use at Facebook is rather specific to our environment, and likely won't be as useful to the open source community. For more general use outside of Facebook, it should be possible to modify existing open source routing tools to talk to the FBOSS agent, but we have not implemented this yet. In the meantime, we have included a small sample python script in fboss/agent/tools that can manually add and remove routes.

Management Tools

Obviously additional tools and utilities are required for interacting with the FBOSS agent, reporting its status, generating configuration files, and debugging issues.

At the moment we do not have many of our tools ready for open source release, but we hope to make more of these available in the future weeks. In the meantime, the thrift compiler can automatically generate a python-remote script to allow manual invocation of the agent's various thrift interfaces.

Testing Infrastructure

Scripts for system-level testing is included in $base/system_tests/ and documented in the same directory.


See the BUILD.md document for instructions on how to build FBOSS.

Future Development

FBOSS has been designed specifically to handle the needs of Facebook's data center networks, but we hope it can be useful for the wider community as well. However, note that this initial release of FBOSS will likely require modification and additional development to support other network configurations beyond the features used by Facebook. Until it matures more, FBOSS will likely be primarily of interest to network software developers, rather than to network administrators who are hoping to use it as an turnkey solution.

We look forward to getting feedback from the community, and we hope FBOSS can serve as a jumping-off point for other users wishing to program network switches.

FBOSS development is ongoing at Facebook, and we plan to continue releasing more components, additional features, and improvements to the existing tooling.