Certain embodiments described herein are generally directed to deterministic load balancing of processing encapsulated encrypted data packets at a destination tunnel endpoint. In some embodiments, an IPSec component residing within a destination tunnel endpoint is configured to select a CPU core ID of a virtual CPU using a CPU selection function. In some embodiments, the IPSec component selects an SPI value corresponding to the CPU core ID. In some embodiments, the IPsec component indicates the SPI value to a source tunnel endpoint for use in establishing an in-bound security association, wherein the in-bound security association is used by the source tunnel endpoint to encrypt a data packet received from the source endpoint and destined for the destination endpoint.