NVIDIA DOCA HBN Service Guide
This guide provides instructions on how to use the DOCA HBN Service container on top of NVIDIA® BlueField® networking platform .
Beyond this page, the content of the HBN Service Guide is distributed across the following subpages:
Host-based Networking (HBN) is a DOCA service that enables the network architect to design a network purely on L3 protocols, enabling routing to run on the server-side of the network by using the BlueField as a BGP router. The EVPN extension of BGP, supported by HBN, extends the L3 underlay network to multi-tenant environments with overlay L2 and L3 isolated networks.
The HBN solution packages a set of network functions inside a container which, itself, is packaged as a service pod to be run on BlueField Arm. At the core of HBN is the Linux networking BlueField acceleration driver Netlink-to-DOCA, or nl2docad. This daemon seamlessly accelerates Linux networking using DOCA APIs to program specific packet processing rules in BlueField hardware.
The driver mirrors the Linux kernel routing and bridging tables into the BlueField hardware tables by discovering the configured Linux networking objects using the Linux Netlink API. Dynamic network flows, as learned by the Linux kernel networking stack, are also programmed by the driver into BlueField hardware by listening to Linux kernel networking events.
The following diagram captures an overview of HBN and the interactions between various components of HBN.
ifupdown2 is the interface manager which pushes all the interface related states to kernel
The routing stack is implemented in FRR and pushes all the control states (EVPN MACs and routes) to kernel via netlink
Kernel maintains the whole network state and relays the information using netlink. The kernel is also involved in the punt path and handling traffic that does not match any rules in the eSwitch.
nl2docad listens for the network state via netlink and invokes the DOCA interface to accelerate the flows in BlueField hardware tables. nl2docad also offloads these flows to eSwitch.
Service Function Chaining
HBN is a "bump-in-the-wire" service and requires specific network configuration on BlueField called service function chaining (SFC). SFC configuration is used to redirect network traffic, which is originated from or forwarded to the host or BlueField itself via the HBN data plane.
The diagram below shows the fully detailed default configuration for HBN with SFC.
In this setup, the HBN container is configured to use sub-function ports (SFs) instead of the actual uplinks, PFs and VFs. To illustrate, for example:
Uplinks – use p0_if instead of p0
PF – use pf0hpf_if instead of pf0hpf
VF – use pf0vf0_if instead of pf0vf0
The indirection layer between the SF and the actual ports is managed via a br-hbn OVS bridge automatically configured when the BFB image is installed on BlueField with HBN enabled. This indirection layer allows other services to be chained to existing SFs and provide additional functionality to transit traffic.
