Processing packets by an offload platform adjunct to a packet switching device

In one embodiment, an offload platform is an compute platform, adjunct to a router or other packet switching device, that performs packet processing operations including determining an egress forwarding value corresponding to the next-hop node of the packet switching device to which to send an offload-platform processed packet. The offload platform downloads forwarding information from the router, and augments it, such as, but not limited to, representing interfaces of the router as identifiable virtual interface(s) on the offload platform, and including each of one or more next-hop nodes of the router represented as an identifiable virtual adjacency and identifiable tunnel (e.g., identified by the egress forwarding value). In one embodiment, the egress forwarding value is an Multiprotocol Label Switching (MPLS) label or Segment Routing Identifier. The router identifies packets of certain packet flows to send to the adjunct offload platform, rather than processing per its routing information base.