Hi Robin,

On 3/23/2026 9:54 AM, Robin Jarry wrote:
Vladimir Medvedkin, Mar 22, 2026 at 16:42:
This series adds multi-VRF support to both IPv4 and IPv6 FIB paths by
allowing a single FIB instance to host multiple isolated routing domains.

Currently FIB instance represents one routing instance. For workloads that
need multiple VRFs, the only option is to create multiple FIB objects. In a
burst oriented datapath, packets in the same batch can belong to different 
VRFs, so
the application either does per-packet lookup in different FIB instances or
regroups packets by VRF before lookup. Both approaches are expensive.

To remove that cost, this series keeps all VRFs inside one FIB instance and
extends lookup input with per-packet VRF IDs.

The design follows the existing fast-path structure for both families. IPv4 and
IPv6 use multi-ary trees with a 2^24 associativity on a first level (tbl24). The
first-level table scales per configured VRF. This increases memory usage, but
keeps performance and lookup complexity on par with non-VRF implementation.

Vladimir Medvedkin (4):
   fib: add multi-VRF support
   fib: add VRF functional and unit tests
   fib6: add multi-VRF support
   fib6: add VRF functional and unit tests
Hey Vladimir,

Thanks for the series, this is an interesting approach. Does this allow
sharing the tbl8 arrays amongst VRFs?

Yes! tbl8 array is shared for all VRFs in both IPv4(dir24_8) and IPv6(trie).

--
Regards,
Vladimir

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